(Added: To see the best advice in this thread, read this summary.)

This is a thread for practical advice for preparing for the coronavirus in places where it might substantially grow.

We'd like this thread to be a source of advice that attempts to explain itself. This is not a thread to drop links to recommendations that don’t explain why the advice is accurate or useful. That’s not to say that explanation-less advice isn’t useful, but this isn't the place for it.

Please include in your answers some advice and an explanation of the advice, an explicit model under which it makes sense. We will move answers to the comments if they don't explain their recommendations clearly. (Added: We have moved at least 4 comments so far.)

The more concrete the explanation the better. Speculation is fine, uncertain models are fine; sources, explicit models and numbers for variables that other people can play with based on their own beliefs are excellent. 

Here are some examples of things that we'd like to see:

  1. It is safe to mostly but not entirely rely on food that requires heating or other prep, because a pandemic is unlikely to take out utilities, although if if they are taken out for other reasons they will be slower to come back on
  2. CDC estimates of prevalence are likely to be significant underestimates due to their narrow testing criteria.
  3. A guesstimate model of the risks of accepting packages and delivery food

One piece of information that has been lacking in most advice we’ve seen is when to take a particular action. Sure, I can stock up on food ahead of time, but not going to work may be costly– what’s your model for the costs of going so I can decide when the costs outweigh the benefits for me? This is especially true for advice that has inherent trade-offs– total quarantine means eating your food stockpiles that you hopefully have, which means not having them later.

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Since COVID usually kills via pneumonia, and insufficient vitamin D appears to be a surprisingly large risk factor in respiratory infection, it’s probably pretty important to keep vitamin D levels sufficient (which in most people means supplementing it specifically, esp if there’s any quarantine that affects food).

Amazon link


  • Study says 4x rate of respiratory infection in the very deficient, but doesn’t see an obvious effect in the partially deficient, so slightly weird statistics.
  • Study says very large effects in children
  • WHO says linked
  • Study says no effect from supplementing after already sick, so get on this before infection

Note: In the summary post, this comment thread suggests getting only normal amounts of vitamin D.

From Lifestyle interventions to increase longevity:

There’s also the bad news that multivitamins mostly don’t do anything. There has not been found an alternative to eating a variety of nutrient-dense whole foods. Though vitamin D supplementation appears to be quite beneficial.

(FWIW, I just purchased from the Amazon link!)

It seems to me like this study wasn't very good and I've been more convinced by the rebuttals, such as this one: https://www.youtube.com/watch?v=o0u8UdZeOhc

Scott Alexander says Vitamin D is (TL;DR) just good for bone health, even though studies exist saying otherwise.



I'm leaning on the expected value rather than robust evidence. Definitely seems plausible to me that it's not useful for immune function outside bone health. But priors (it's the one vitamin not in diet, so everyone is deficient) and the small amount of evidence are enough to make me think it's net-positive, and even 20% likely to help by a small amount is a relatively large benefit (~ a day of life). It seems hard enough to find small effect sizes of things via study that I'm not at all surprised meta-analyses showed no evidence for it—and when I don't really expect to see evidence, defaulting to "do what seems like it would be healthy in the ancestral environment" says sunlight is probably a better bet than supplements, but being non-deficient in vitamin D is probably a better bet than being deficient. (And again, this doesn't apply to other vitamins because they're in the diet. It does apply to e.g. sleep and exercise though.)

Incentive sperometers are often used for the prevention of pneumonia. Maybe this suggests using those as well?

Good call, these are indeed useful, though I'm not sure if worth it. Guessing 20 mins total for vitamin D for a 3x decrease in 10% of the population is roughly a 7% risk reduction, while maybe 10 hours on the spirometer for a ~~3% effect? (Eyeballing this study in pneumonia sequelae looks like an 80% effect from this over 2 years, plus other interventions.) If this thing on average knocks 2 months off my life, a 3% effect is still 2 days, plus you get other health benefits, BUT if I'm planning on quarantining hard enough to not get it, the benefits do go down.

What would be the appropriate dose of Vitamin D?

The large effects on children is an odd example (poor example?) to point at since children have been reported to have the least harm from COVID-19.

1000-2000IU on average per day for an adult, depending on your size. You add this up and take it instead every 2-3 days likely without any issues (e.g. I take 3000-4000IU every 2-3days) If you have lighter toned skin and get regular sun exposure you may not need any supplementation

Is there any reason to worry copper tape might be less effective than the copper used in experiments? (I haven't read methods to see if they describe the source of the copper) For example, a lot of copper is designed to be resistant to oxidation - does that matter?

You can get vitamin D from sunlight exposure. For white people, this doesn't take long, probably minutes (around noon) of direct exposure on your face and arms. If your skin is darker, it takes longer. You have to expose more skin for longer periods. Black people maybe can't get enough at high latitude and will have to take the pills. If you're supplementing this way, you do have to actually step outside for a bit. Exposure through windows that block UV is not going to work. Obviously, sunscreen will prevent some exposure.

If you get a sunburn, you waited t

... (read more)



Advice: Use gloves or wash your hands after handling delivery packages, and be careful not to touch your face while handling them.


  • Packages have been handled by many people, who have economic incentives to come to work even when sick
  • Coronavirus has a long asymptomatic but infectious period
  • -> Once coronavirus is at all prevalent, your packages will be exposed
  • Coronavirus can live on surfaces for many days (my research)
  • Cardboard is hard to sterilize (I'm still investigating this one)
  • -> You're likely to pick up virus particles on your hand from handling packages
  • Washing is effective at clearing virus particles off of your hands
  • Unless you've already transferred them to mucous members by touching your face.

In photos of Amazon fulfillment centers, the workers appear to mostly be wearing fabric work gloves, not disposable gloves. Workers touch both the outer cardboard box and the item; but if the item has its own packaging, anything inside of that will probably have been untouched since manufacture, which is probably long enough.

I wrote a post with a comprehensive disinfection protocol here, although some criticized it for being excessively paranoid.

I also spray all deliveries with disinfectant and put them for a waiting room for days. Also disinfect floor where they were and the bottoms of my shoes.

I haven't been able to find anything on the effectiveness of disinfectant on cardboard. Do you have any pointers?
What I know from clean rooms in the biopharmaceutical production is that you avoid there cardboard at all because there is no straightforward way for disinfection (besides the particulate contamination that comes with them). Therefore, one approach is to remove the cardboard as soon as possible and put it away (and wash your hands afterwards). Edit - Additional comment to make the statement more precise: There is no straightforward way for disinfection of cardboard without destroying it, i.e., the cardboard soaks in the cleaning agent and will disintegrate.

Do you mind elaborating on how you reconcile your model with the 1st CDC link you list in your research? "In general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from products or packaging that are shipped over a period of days or weeks at ambient temperatures" And my interpretation of the 2nd JHI link is that since cardboard is perhaps closest to wood/paper, then the persistence is about 1-4 days, which seems to indicate a relatively low risk (at least compared to other surfaces). I think taking your advice is reasonable because it only increases safety; I just wanted to better understand what we think the risk level is.

1. I don't particularly trust the CDC on this 2. The CDC is talking specifically about infection from China (I assume this was written when CoV was more contained), and I agree that typical transit time from China is long enough to let the virus die. I'm specifically concerned about the delivery person and the dude at the Amazon warehouse who packed the box.

How about using UV lamps and ozone in bathroom to sanitize the deliveries? This might be particularly useful for groceries.

Please don't use ozone - https://www.lesswrong.com/posts/LwcKYR8bykM6vDHyo/coronavirus-justified-practical-advice-thread?commentId=qRnqPAThJEJp9ySkE

Unexpected difficulty: if I open packages with scissors wearing gloves, I tend to cut my gloves. Maybe this would work better now that I have a box cutter?

Use hand sanitizer or wash hands with soapy water frequently- after touching any doorknob exposed to an epidemic, at a minimum. (This includes doorknobs that only you touch, if there's a chance that you're in an infections asymptomatic state). Other triggers include the normal cases of before cooking and before eating.

What does frequently mean? Whatever your answer, why that, instead of 10% more or 10% less? Discussion from another post about the payoff of handwashing in general and how to determine the right frequency: https://www.lesswrong.com/posts/ztDYsD4v7AaAbWEDM/some-quick-notes-on-hand-hygiene#9jW5reovD4cMeXcZh



Tl;dr Putting copper tape on commonly-touched surfaces is a high-value thing to do in the case you’re actively trying to avoid infection, since copper kills viruses and ~~50% of viral disease is from hand-to-surface-to-face contact (h/t Adam Scholl for hypothesis) [ETA: coronavirus seems to have mostly (?) respiratory droplet transmission, so this prior is less relevant but still worth intervening upon]

Amazon link (sadly, probably one Amazon item that won’t go out of stock)

Metals killing bacteria is well-documented, like all the very consistent results in this paper comparing 9 metals (lead kills slightly better than copper but that unfortunately extends to the humans; zinc and some other metals also kill pretty well, only two did not). Within an hour, copper dropped CFU from 10^6->10^1 (the measurement threshold). Zinc took 2 hours, nickel 4.

Unfortunately, this isn’t in widespread use in hospitals yet. But when it does, copper on the most-touched surfaces of an ICU appears to reduce infections by about half (bed handles, chair armrests, nurse call buttons, and a few others). But these are in very high-germ-load environments. What happens in a normal home?

First, how much of disease spread is from hand-to-surface vs airborne or hand-to-hand? I lost the citation and it wasn't well backed, but apparently you don't catch colds through suspended particles very often (someone has to sneeze within 6 feet or exhale in your face lots). And hand-to-hand contact spreads it more efficiently but (one paper said) less frequently than hand-to-surface-to-hand, especially in environments without lots of high-fiving and hand-shakes. Plus, the study saying 50% infection reduction from copperizing main surfaces would fit well with a base rate of ~70% hand-to-surface infections and, of these, ~70% of touches in the ICU got sanitized by the dangerous surface metal coverings. But 70% sounds like a lot so I’m going to be a little conservative and just say 50%.

Now, it’s hard to figure out how many things you’d need to cover with copper to reduce most of this. But some typical commonly-touched shared items are:

  • doorknobs (brass is probably ok, steel is not) [ETA: comment below points out brass not ok]
  • light switches
  • faucets
  • toilet handles
  • refrigerator
  • drawer handles
  • writing implements
  • backs of chairs

Depending on how many people you are sharing touch-space and not air-space with, I expect covering these in copper could reduce infection by anything from 1 to 50%, though I expect in a typical house of four people who sometimes venture outside and don’t know about never touching your face, you’d get an effect roughly between 15 and 40%.

[UPDATED, thanks to various people who caught errors in V1 and pointed out V2] New NIH study of COVID half-life in aerosol or on surfaces V1 with errors: https://medrxiv.org/content/10.1101/2020.03.09.20033217v1 , V2 hopefully error free: https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v2.full.pdf (H/T @AndyBioTech)

2.4-5.11 hours on copper, in contrast to 10.5-16.1 on steel or 13-19.2 on plastic

This study describes "detecting viable virus" as having a threshold of 10^0.5 TCID50/mL, and they assume exponential decay of viable virus particles. 

I'm really confused by their numbers, tho; it looks like cardboard has a hundred-fold reduction in 23 hours, from 10^2.5 to their detection threshold of 10^0.5, which I can't square with the 8.5 hour half-life. [Edit: it looks like I'm potentially confused about what TCID50/mL means?]

I also don't know how to compare their detection threshold with the point at which I should be willing to handle a cardboard box (with varying levels of cleaning and PPE). Is their test basically as sensitive as my immune system (in that I shouldn't handle something where they could see a viable virus, and can handle something where they can't)? Or should I be letting boxes sit for 3 days?

I had the same confusion over the half life ratings. TCID50/mL is how much you can dilute a sample and still have it kill half of the cells in a sample. This suggests that the natural reading of those graphs is correct. I estimated some numbers off the graph and it looks like what they are calling half-life is actually 1/5th life, so either we're both missing something important or there is an error somewhere.
I've emailed the author; we'll see if she has time to respond (or if the code goes up on Github; I can't find it yet).
Looks like v2 of the paper has corrected the error.
See here: https://www.lesswrong.com/posts/B9qzPZDcPwnX6uEpe/coronavirus-justified-practical-advice-summary?commentId=LuJRfhrNhu4aBanQn

Worth noting that a lot of metal handles will be coated with a finish that prevents you from actually touching the metal. This is because these metals (especially copper) can leave a strong metallic smell on your hands which people typically dislike, and also because it prevents the metals from tarnishing. These handles will not help reduce infection and will need copper tape on them.

Killing bacteria isn't the same as killing viruses. Do we have reason to expect the same efficiency?

Sorry, forgot to modify this for a virus-specific claim, but yes.

On solid copper, H1N1 decreased by 4 logs in 6 hours in this review; vaccinia and monkeypox viruses were reduced by 6 logs in 3 minutes in this study; murine norovirus was destroyed in 30 minutes in this study, though it doesn't work very well at 4C; and another review says that copper oxide filters neutralize all of "bacteriophages [58-62], Infectious Bronchitis Virus [63], Poliovirus [61,64], Junin Virus [59], Herpes Simplex Virus [58,59], Human Immunodeficiency Virus Type 1 (HIV-1) [11,65-67], West Nile Virus [11], Coxsackie Virus Types B2 & B4, Echovirus 4 and Simian Rotavirus SA11 [68]. More recently, the inactivation of Influenza A [55,65], Rhinovirus 2, Yellow Fever, Measles, Respiratory Syncytial Virus, Parainfluenza 3, Punta Toro, Pichinde, Adenovirus Type 1, Cytomegalovirus, and Vaccinia [65]".

In this context, is a log a factor of 2, or of 10 (or of e)?
Medical doctors, so 10
Wikipedia suggests copper can kill at least influenza A virus and adenovirus. It seems likely that it would be effective against other viruses too, though not clear (to me) if it would work against every virus.

This ERI review concludes that there was really only one RCT (the one you linked), and they found that the study didn't actually reach significance

Our calculation found that the difference in the HAI rate (regardless of MRSA/VRE colonization status) between the study groups was not significant (copper-equipped ICUs: 17/294 [5.8%] versu snon-copper-equipped ICUs: 29/320 [9.1%]; p=0.123). The median length of stay for both groups was four days (p=0.74). The reported mortality rate was 42/294 patients (14.29%) in copper-equipped ICUs versus 50/320 (15.63%) in non-copper-equipped ICUs(p=0.64).

What's going on here is that Salgado splits outcomes into 4 groups, nothing, infection, colonization, and both, and finds a difference between the 4 groups. The review says "I only care about infection" and compares infection vs non-infection, and finds no significance. Each version of their math checks out, but I'm inclined to trust the review here.

This quasiexperimental study found similar decreases in infection rates however.

I'm not sure how to evaluate this evidence, but I'd be cautious about taking the Salgado results on its face.

If it's a cheap countermeasure that aims, in the better estimate, for a 50% reduction of a small risk I think you'd be better off asking yourself if you'd buy it at double price rather than deciding which of the equally persuasive, conflicting experimental evidences about its efficacy you should trust. Also if you're worried about non monetary costs like hand skin damage, I guess you'd better decide if you'd put up with the same cost for a 25% risk reduction.

Earlier I heard something like "wrinkles in the copper can reduce the effect, something something the fluids get caught in little pockets and leave spots that don't touch the copper."

Have you heard anything about that and have any thoughts on that? A lot of the images I see of people coppering their doorknobs are particularly wrinkly, and I'm wondering how much effort to put into getting everything smooth.

Not that it's necessary to make this comment complete, but I'd love to hear more about that 50% estimate. I've had a very hard time getting data on that.

5Ben Pace

Do you expect this to work for copper that has oxidized? Our bathroom copper is turning green and not sure if it's still doing anything.

Oxidized copper has actually shown*increased* anti microbial activity in some studies IIRC. Also this https://www.sciencedirect.com/science/article/pii/S0010938X17313963

The document referring to copper that I found via SSC was https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3067274/ .

The time of contact killing listed among the different microbes ranges from 1 minute to over a week. I don't know which example of a microbe would be closest to copper.

One big problem that may exist with using copper that I came across is that copper may reduce in efficacy if it is frequently cleaned, whereas stainless steel is fine to repeatedly clean. Source

The cleaner suggested to be used on copper surfaces without reducing its effic... (read more)

Is there a reason we're not spamming reddit/discords etc. with this advice?

I don't have enough karma on reddit to do things, but r/china_flu, r/lifeprotips, r/todayilearned all seem like good places to post this information.

Additionally, it might be worth it to spam amazon listings of copper tape with reviews saying it has antiviral properties. Possibly contacting the sellers of the tape as well.

Because 'spamming' is a rude way to force people to pay attention to you, and should be discouraged. But posting the information in ways that follow community norms seems good, although I'd want to think a bit about prioritising messages to spread - quite plausible to me that advertising the need for expanded capability to supply oxygen to people is more important.
Note that sellers probably can't make claims about this without running into legal tape.

Living in a group house? Consider copper tape on:

Front door handle

Bathroom door handle and sink handle

Refrigerator Door handle

Kitchen trash lid handle if not touchless

Microwave handle + small square of cutout copper tape on '+1 minute' microwave button

That seems useful. You forgot one of the most commonly touched items - phones and computers. I am gonna put tape on the back of my phone case and my laptop.

This is a good point, but for what it's worth I don't fully endorse coppering your phone (mine isn't coppered). Several people have anecdotally reported it being uncomfortable or irritating on their hands, or receiving tiny cuts from the copper, etc.

Absorption through skin is incredibly low, but I do take the risk of open (if tiny) hand wounds seriously, and also generally try to reduce my total copper contact in case anything weird does happen, since this is not tested by time.

Some discussion of whether wearing copper jewelry causes unsafe exposure to toxic copper compounds: https://orchid.ganoksin.com/t/verdigris-poisonous-copper-compounds/42591 Seems like the case for copper on door handles is stronger than the case for copper on your phone, laptop palm rests, etc.
You touch these often, yes, but how often do you share them with other people? If all the germs on there are yours, maybe disinfecting it is not really helping.

But if you are constantly handling your phone it will reduce the value of frequent washing/sanitizing of hands, since anything you do get on your hands will transfer to your phone.

Although, I don't know what the numbers look like for transferring virus when a touch occurs -- e.g. if we look at a path like "handshake -> touch phone -> [wash hands] -> touch phone -> touch face", how much of the virus is left after four sequential touch events like that? Perhaps this kind of secondary contamination is not actually a huge deal? I have no idea.

I guesstimate the deal is not negligible. Input to my intuition: (source http://theconversation.com/atms-dispense-more-than-money-the-dirt-and-dope-thats-on-your-cash-79624 ) A powder called Glo Germ, meant to visualize germ spread, was still visible to the naked eye after 8 handshakes (but not 9) in an informal experiment by YouTuber Mark Rober. ( https://youtu.be/I5-dI74zxPg?t=346 )
This is my usual attitude, but given the evidence that coronavirus is very long lived on surfaces and reinfection is possible, it seems worth it to me in this specific case.
[This comment is no longer endorsed by its author]Reply



Edit: Sounds like this isn't very useful because you'll be able tell if you're having trouble breathing? See comment below.

Advice: Get a pulse oximeter to be able to triage at home.

Reasoning: If you're mildly sick, you probably don't want to go to a medical office (both because you'll be clogging up an overcrowded system, and because you'll be around people who are even sicker). But you need to know when you're sick enough to need medical care.

One way medical professionals triage is by vital signs. Most of them are obvious either to you or to other people (shortness of breath, paleness, dizziness, turning blue) but oxygen saturation (how well-oxygenated your blood is) is not. If you think you might have pneumonia (one of the common effects of coronavirus), low oxygen saturation is one of the things that would indicate that, and lower numbers should move you toward getting medical care. 95% and above is normal (at sea level) and lower numbers mean it's likely your lungs aren't working properly (with outcomes being worse the lower the number is).

The device is cheap and easy to use.

Note that you might still be very sick and need medical care even if your oxygen level is fine, so this is a way to rule in being sick enough to need medical care but doesn't rule it out.

Guide to using and what levels are normal

More detailed instructions for troubleshooting

Article on lower oxygen saturation meaning worse outcomes for pneumonia

(I'm not a medical professional and would appreciate it if someone who is would double-check the logic here, or some risk I'm not thinking of in terms of people reading it wrong and coming to wrong conclusions)

TL;DR. If you have (slightly) low PaO2, but no trouble breathing, you probably don't need to go to the hospital. And if you have trouble breathing, you should probably go to the hospital whether or not you have low PaO2. So testing for oxygen saturation doesn't add much.

I had an online conversation with an intensive care physician. I sent him a translated version of juliawise's text and he said he didn't think buying the pulse oximeter would help and then sent me a 5 minute audio explaining why. The following text is his audio translated from Portuguese to English, I hope there are no wrong translations and I changed my mind after listening to him. Please also share what you think about his response:

"All pneumonia will desaturate the patient. O2 saturation is related to perfusion (gas exchange). Patient with acute respiratory syndrome (inflammation of the lungs by viral or bacterial infection) may course with poor tissue perfusion, that is, inadequate tissue oxygenation. One way to evaluate this is pulse oximetry, PaO2.

Patients with respiratory discomfort due to lung inflammation may or may not present desaturation. PaO2 < 90 indicates oxygen therapy. ... (read more)

This comment could maybe use a tl;dr saying:

If you have (slightly) low SpO2, but no trouble breathing, you probably don't need to go to the hospital. And if you have trouble breathing, you should probably go to the hospital whether or not you have low SpO2. So testing for oxygen saturation doesn't add much.

Is there any info the comment was meant to convey that that leaves out?

5Filipe Marchesini
Thanks for the suggestion, ESRogs. I'm adding the shortened version now.
According to this NYT article, Covid pneumonia often (in most cases?) initially causes low blood oxygen without obvious respiratory discomfort or shortness of breath ("silent hypoxia"), and early detection of this can be critical. If true, it is a very strong argument in favor of pulse oximeter.

There seems to be a general variance in what pulse oximeters display when measuring healthy individuals with readings from 94% - 100%. I also seem to remember reading that they are sensitive to altitude, whether hands are cold etc (n.b typing on phone, can't verify at the mo)

Talking to a doctor friend -- in clinical settings if an oximeter shows a reading < 90%, it's considered serious, but different people respond differently, but closely enough for the purposes of this discussion to fall into two groups. Either you develop a shortness of bre... (read more)

It seems to me that the usefulness of a pulse oximeter depends on the progression of the disease. If "low osat" comes before "fever etc", then a pulse oximeter would help you move from "low osat → fever etc. → see a doctor" to "low osat → see a doctor → fever etc.". But if "fever etc." comes first, I would think you would be at "fever etc. → see a doctor → get osat measured" regardless of whether you have a pulse oximeter, and so I don't see how the p... (read more)

This is useful in case you have facing a choice of riding it out at home and going to a hospital with high probability of getting infected if you're not already. E.g. if you have fever chances are still high you're just experiencing regular flu, and should not go to the hospital, but if your oxigen starts dropping into the danger zone you need to go.

This site provides link for medical kit. You can copy and paste the supply list rather than purchase, or follow link to each item.

The logic is to "save you a trip to the doctor, or to support remote care via phone/video chat. " Recommended diagnostic tools are digital thermometer, finger oximeter, blood pressure cuff, and stethoscope for lung sounds.

In order to avoid cross infection, it is a good idea to use telemedicine rather than emergency room or doctors' offices.

Suggestion: research options for video chat, text messaging, or emailing d... (read more)

Where would you buy one and what brand?

1Chris Hibbert
I saw an earlier recommendation and went to Amazon. They have pages of them, differentiated by color and style, which made me realize they are a commodity, in common use among a particular large population of at risk people. They're not covered by health insurance, so there's actual competition. Look at the ratings and use your usual yardsticks to pick ones that people who have bought before find to be reliable and useable.



You should have some kind of electrolyte powder or electrolyte drinks on hand. When sick with any disease that can cause a fever (Fever is one of the symptoms of COVID-19 that pretty much everyone gets), staying hydrated is possibly the most important thing for you to be doing. You may be losing fluids from sweating and you may not be paying much attention to how much you are drinking. You will do a better job staying hydrated if everything you need to be hydrated can be right next to your bed. Once you have a fever it will really suck to go acquire stuff and you should be staying at home anyway.

Don't bother with the drinks. Recommended home-made rehydration drinks usually are sugar + salt for electrolytes. You want ~12x as much sugar as salt, and if you want to prep early, you can store the sugar-salt mixture and add it to water - you want about a half tablespoon of the mixture pur cup of water.


Unless this is the only thing you have to eat/drink for more than a couple days, this is fine - no need for anything complicated or expensive. And if you're too sick to eat solids or other foods, I'd suspect you don't have COVID-19, you have something else.

Can you respond directly to the claims that potassium and magnesium are also useful? It seems like your implicit model is that people will definitely be able to eat and therefore those will not be a concern.

I'm not sure I understand the question, exactly. Yes, lots of things are useful, like vitamin D, Zinc, and Potassium - but they aren't important for preventing dehydration, and the WHO recommends using the above sugar + salt formula for home preparation, which is why I pointed out that it's recommended. If you want to buy Soylent, or Gatorade, or anything else, go ahead, but if you're trying to prevent dehydration, there's no need to buy any specialized drinks.
Re. potassium, I buy a low-sodium salt because it's usually high in potassium.
(Also, instant soup mix + hot water is a perfectly good replacement when you have a fever, as long as you're not actually getting severely dehydrated, say, due to diarrhea.)
Where does the 12x come from? The link mentions 1/2 a tablespoon of salt versus 2 tablespoons of sugar, which is a factor 4 in volume. A quick google says the densities only differ by 25% (and in the direction that makes the ratio closer, not further apart), so this is not mass percentage either. EDIT: Never mind, they mention 1/2 a teaspoon of salt. My mistake.

What happens when your electrolytes get low? I just have a vague sense that it's bad.

Main electrolytes : Sodium, chloride, potassium, calcium, phosphate, and magnesium. Low electrolyte conditions if you want to check specifics: hyponatremia (sodium), hypochloremia (choloride), hypokalemia (potassium), hypocalcemia (calcium), hypophosphatamia (phosphate), hypomagnesemia (magnesium). Electrolyte imbalances are more of a concern with severe vomiting/diarrhoea conditions rather than with running a fever. (unless severe and prolonged sweating or underlying conditions). Fever = increased sweating. Sweat = water and mainly sodium and chloride. * An easy check is to taste your sweat. If it's salty, you're OK. * Monitor the colour of your urine - pale yellow (straw coloured) suggests adequate hydration. Hydration is important to maintain. Plain water is usually sufficient. Little and often. (Too much water can also be dangerous i.e. don't be drinking a litre at a time). 0.9% NaCl solution is isotonic ("normal saline " I.V fluids) Standard practice for homemade "electrolyte solution" is a pinch of table salt and a level teaspoon of sugar in a pint of water.

Probably stupid question, but why electrolyte drinks rather than just water?

6Thomas Kwa
Your blood normally contains around 140 mmol/L of sodium, and smaller amounts of calcium, magnesium, and potassium. Sodium is the most important of these and has the narrowest normal range (135-145 mmol/L). Except for calcium (which can be taken from your bones) there is little storage. In normal circumstances you don't lose much water and can get sufficient electrolytes from food, but during fever your fluid loss rate can easily be increased by multiple liters per day, and you may be eating much less as well.

What's the advantage of electrolytes over just table salt?

Magnesium and Potassium, mostly.
This changed my mind, thank you.
I'm not sure if electrolyte powder is more hydrating than salt. . . But I think there's a lot to be said for making water taste good enough to you that you want to keep drinking it. Often things taste worse than usual when sick and having something you can mix with water that tastes good will make you more likely to keep drinking it. For the same reason I try to have a variety of hydrating things I'm willing to drink around so when one gets old I can switch to a different one.
It includes potassium in right proportion.
I am wondering this too. I think they contain more of the essential compounds we need need for our water/"salt" balance. Like, not just sodium and chloride as in table salt, but also maybe potassium and calcium? Store bought "potassium salt" provides you everything but the calcium, unsure about the proportions though. Also, it looks like not all "electrolytes" contain calcium anyway. Eg this one just contains potassium, sodium and chloride and zinc: https://www.target.com/p/pedialyte-advancedcare-electrolyte-solution-tropical-fruit-33-8-fl-oz/-/A-21538752



Hospitalization and oxygen therapy thresholds

Tl;dr: Not knowing much about this and not a doctor, my current policy is to go to a hospital if SpO2 drops below ~92% and my hospital isn’t completely overrun, unless my SpO2 is naturally low or some other extenuating circumstance. If I was forced to use an oxygen concentrator outside of a hospital, I would target a ~~94-96% SpO2 range, trying very hard to make sure I didn’t hit 99%

If you do have COVID and shortness of breath, when do you go to a hospital?

Hopefully you already have a pulse oximeter as Julia Wise recommends. But sources say anywhere between 90 and 95% SpO2 is the threshold for hospitalization (WHO says <= 93% is classified as severe, ctrl+f “O2”), while other sources say you should threshold on trouble breathing and shortness of breath, not the actual SpO2 number.

It seems to me that using “trouble breathing” as the indicator would track the lung blockages and thus immune response relatively well, while O2 as an indicator would track the danger metric directly (if in fact the primary source of death is insufficient oxygen; if anyone knows this, would be useful).

The benefit of looking at trouble breathing is that it’s an advance indicator. Usually people progress from oxygen therapy to ventilators relatively quickly. If you have naturally low SpO2, your O2 might drop under threshold (say, 93%) in the early stages with mild trouble breathing, but you wouldn’t have much of a dangerous immune response until later. In this case, you’d have wanted to use difficulty breathing as your indicator instead of SpO2.

That being said, having low oxygen seems pretty bad for you, both by common sense and science. For example, 92% or lower is associated with increased morbidity in pneumonia patients; <90% is increased with 36% increased morbidity. Since it’s hard to measure even moderate effects due to the treatment-correlated-with-severity issue, my guess is that there’s some general bodily harm from reduced oxygen even at levels like 95%, though I don’t know how much. So at some SpO2 threshold, I think you want to be supplementing oxygen even if your breathing doesn’t feel that difficult.

Unfortunately, it seems like you can’t supplement oxygen at 95%, because over-oxygenating causes neuronal damage. Standard targets appear to be 94-98% or 92-96%. This study says it seems bad to set your target range during oxygen therapy to greater than 92-96%, because one inevitably exceeds the upper target occasionally. This review/musing muses that it’s a difficult problem, evidence for hyperoxaemia being pretty bad is “comparatively strong”, but not strong enough to warrant especially conservative oxygen titration. Because of these numbers, I think 92-93% is a reasonable threshold to self-hospitalize, since anything above this means they probably shouldn’t be oxygenating you anyways.

If hospitals are overloaded and you have to do oxygen therapy yourself (really try not to do this), I think the targets above are still reasonable, subject to your ability to titrate well with the machine. If you have lots of trouble, of course be conservative. However, you may be able to do better than hospitals: the first study above says that “even in a research setting in the intensive care unit, in which patients receiving mechanical ventilation are closely monitored, most patients who were randomized to an SpO2 target of 90–92% and were receiving supplementary oxygen did not have their inspired oxygen reduced if the SpO2 was 99% or 100%.” So—seems like you could easily do better monitoring than this if you were oxygenating at home. This is why I would probably shoot for 94-96% myself.



Hand sanitizer is becoming hard to find. Here are some WHO guidelines on making your own :


Formula 1:

• Ethanol 96%: 8333 ml • Hydrogen peroxide 3%: 417 ml • Glycerol 98%: 145 ml

Formula 2:

• Isopropyl alcohol 99.8%: 7515 ml • Hydrogen peroxide 3%: 417 ml • Glycerol 98%: 145 ml

Edit: Top off with distilled water until you get 10L of product.

My justification is argument from authority. I have no explicit model. Although both formulas use high concentrations of alcohol which are known to be effective disinfectants.

(FactorialCode has fixed it.)

The formulas above are incomplete. You have to fill them up to ten litres with water. Thus it is written in the PDF.

(As far as I know, too high an alcohol concentration makes the sanitizer less effective.)

Good catch.

If 99%+ isopropyl alcohol becomes unavailable, it looks like the other common concentrations are 70% and 91%. Using 70% isopropyl alcohol and not diluting gives you 65% alcohol, which is below the 75% in the recipe-- anyone know if 65% is likely to be effective?

In that case you can use the straight 70 % isopropyl alcohol as a sanitizer and be fine. According to the WHO guidelines, only the isopropyl alcohol is the effective substance in the recipe. The hydrogen peroxide is ‘used to inactivate bacterial spores in the solution’. If you buy medical-grade 70 % isopropyl alcohol, there shouldn't be any bacterial spores in it. The glycerol serves as a humectant. If you don't add it, you might have to use more sanitizer in order to keep your skin wet for the whole thirty seconds. And you'll have to keep your skin happy in some way separate from the sanitizing.

Hand sanitizer is a poor substitute for actually washing your hands with soap and water.

Coronaviruses are "enveloped" viruses, which means they have a fat-based shell that protects the genetic material and (presumably) aids it in infecting a cell.

Destroying this shell "kills" the virus.

While an alcohol sanitizer can of course dissolve the fats in the shell, it is difficult to get enough alcohol all over the skin to do this.

Soap is more effective because it actively attacks fats, and of course washing your hands provides far more volume and time in which to destroy the virus shells.

7Lukas Trötzmüller
What is your source for this? The CDC recommends hand sanitizer in cases where washing is not easily possible. https://www.cdc.gov/coronavirus/2019-ncov/about/prevention-treatment.html Studies confirm the efficacy of hand sanitizer against enveloped viruses [1][2]. Although there is some evidence that handwashing is preferable against viruses [3]. [1] https://academic.oup.com/jid/article/215/6/902/2965582 [2] https://apps.who.int/iris/bitstream/handle/10665/44102/9789241597906_eng.pdf;jsessionid=D50A762FABCFB1569406859669F8FAD4?sequence=1 [3] https://msphere.asm.org/content/4/5/e00474-19

Normally something with AfA as justification would be moved to comments, but it's useful and extremely specific in ways that can still be the foundations for a good argument, so we're leaving it in answers.

I feel like citing WHO is just about as valid as it gets in this context. WHO is just as much "from authority" as citing a few scientific papers.

Ŀady Jade Beacham


The aim of your quarantine procedure and other actions should be to delay your exposure to coronavirus until after the peak has passed. It is unlikely to be possible to delay it indefinitely, especially if we are going to have a return to normalcy.

With every epidemic there is likely to be a peak - a period of exponential growth, climaxing in a peak and then a slowdown. Your goal should be to get exposed after the peak period. During the peak, medical supplies will be stretched very thin and hospitals may be overflowing. After the peak, medical professionals have a lot of experience dealing with the disease and we will know the landscape of outcomes and treatments. As long as the medical systems are not destroyed by the virus, that may be the best time to get it.

I modeled a logistic growth equations for a population of 7 million (bay area) and different estimates of the doubling rate I found in the literature - for a doubling rate of every 3 days, the peak seems to come after about 2 months from initial exposure. For a doubling rate of every 7 days, the peak comes about 4 months after initial exposure. Since the virus has likely been circulating for several weeks already, we can predict the peak in the bay area is 1-3 months out. How it actually plays out will vary a lot based on containment measures, public events, lifestyle of the populace, etc.

This is all extremely speculative but gives me a goal to shoot for - before I was trying to figure out what is the goal of quarantine for myself, if I was ever going to rejoin society. Now I have a model for why I should avoid getting it.

Instead of a single peak moment, we want to think about "the time period during which medical supplies and services are overwhelmed with demand". And that starts, in my rough estimation, the moment all the hospital beds are full.

In the US, we have 3 hospital beds for every 1000 people, and 2 of them are occupied on average. So we're going to start having problems once 1 in 1000 people want to go to the hospital for coronavirus, which corresponds to an infection rate around 1%.

So that pushes the moment of great worry forward by quite a bit!

On the other side, it's hard to predict when supply will again overtake demand. Maybe governmental intervention comes through on a massive scale, maybe mass quarantine works, maybe the weather warms up and transmission declines. But I'm worried it will take months for any of those to happen after the crisis times begin.

I would modify your advice to "2 weeks before all the hospital beds are full (in your local region)", because 2 weeks is roughly the lag time between exposure and needing hospitalization (I think?). With exponential growth @ 5day doubling time, you really want to not catch it when 0.01%ish of the local population is hospitalized [assuming per-capita hospital beds in your region is typical of the USA]. My region has ~7M people, so I would be thinking about upping my social-isolation game when 700 people in my region are in the hospital, or something vaguely like that. Probably adjust that down quite a bit for uncertainty in the input parameters, and for not all cases being diagnosed (even in the hospital). Adjust down even more if lots of hospital staff are likely to get sick or quarantined because they're not taking appropriate precautions, which seems probable at the moment.

6Ben Pace
Why do you believe that about the number of hospital beds? This seems like an important number to have, I wasn't sure of it myself.
Hospital beds per 1000 people - some world data
As leggi said, the USA has about 3 hospital beds per 1000 people, and utilization is about 67%. As for why it's a good proxy... I couldn't think of a better one that's simple and objective. Can you?



[EDIT: enough has been learned since I made this model that it is now deprecated. I am now working from home, indeed 2 weeks after the answer was first composed]

A guesstimate model I made to determine whether I should stay home from work. Most of the innovation is in collecting guesses/gut feelings and then doing the calculations. Based on my guesses, I shouldn't bother working from home for a few months. [EDIT: for complicated reasons it's probably more like one month] [EDIT: after further adjustments, partly to parameters and partly to the structure, it's now like 2 weeks] https://www.getguesstimate.com/models/15212

Meta note: the costs of being isolated are roughly linear in how long you're isolated, but the costs of being in public are exponential in the regime where your chance of getting infected is small and proportional to the number of people who are infected. As a result, you'd rather self-isolate one week early than one week late. Given the model uncertainty in any modelling attempt like this, this means you probably want to be a bit more paranoid than the model suggests.

Model update: previously, the model wasn't including the possibility of a chain of length more than 1 of people infecting each other at work, ending with you. This increases the disease burden of attending work by a factor of 2.

Model update: There's been another confirmed case of community transmission in the Bay Area, so I've updated the number of infections I expect there to be.

Guesstimate model update: Number of days you want to wait until working from home is (unsurprisingly) very dependent on epidemic doubling time estimates. Fiddling with the distribution to basically update on reports of 1- or 2-day doubling times in some contexts, the model now says that I want to wait a month before working from home.

A non-obvious flaw in the model: the "number of days until you should work from home" distribution is using in its calculation samples from the "current dollar value per day of disease burden of attending work", rather than the mean as it should. There's no easy way to fix this, but this pushes that number lower. Note that this error doesn't affect the calculation of whether I should stay home right now. [EDIT: but it does turn "wait a few months" into "wait a bit over a month"]

It looks like you're just assuming how many people will be infected, rather than basing that off current infection levels? Is that correct?

Well, I tried to calculate that off of current infection levels, but indeed that isn't built into the model. I agree that's a big place to change the model.

Note of course that this could be missing obvious factors, if so please let me know.



A 2 weeks supply of food sounds like far too short a supply. The first case of 'atypical pneumonia' was noticed in Wuhan in late Dec. It is now late Feb. They have by now organized themselves in Wuhan to the point where all of the ill people are getting sent to 'local' (temporary) 'hospitals' and the 'local hospitals' are triaging and sending seriously ill people onto actual hospitals with the capacity to care for people who are seriously ill (like requiring oxygen). But this level of organization is a fairly recent situation. Even 2 weeks ago, sick people were literally walking to hospitals, because ambulances were swamped; they were being turned away from hospitals for lack of beds and supplies, and medical personnel to look after them; they were sitting in hospital waiting rooms for hours being cross exposed to other sick people, etc. So, even with massive efforts on the part of the government, it took about 2 months for them to get their act together in a real hot spot of infection. If you are unfortunate enough to end up in a similar type 'hot spot' to Wuhan, (but still live in a first world country) it probably won't take longer than 2 months for the government to get its act together, but I wouldn't assume they will do much better than that... so, if you are planning on buying a little insurance, I'd suggest that a 2 month supply of food, etc, is about minimum of what you would need to get through a (1st world) worst case scenario, rather than 2 weeks.

And a 3 months supply would probably be a better choice than a 2 month supply. It's not like Wuhan is virus free or anything close to it, today, 2 months in...

A 3 month's supply of food sounds crazy, and, true, you probably won't need it. But, it's almost cost free to supply yourself with it. No one at all is suggesting power outages. So, you can probably just stock up on food and supplies you normally use anyway, at least for frozen, canned, and non-perishable type things. That obviously won't do for stuff like milk and fresh fruits and salad stuff, so you'll have to make some substitutions there, but for most other stuff you should be OK if you just buy extras of things you normally buy anyway. The only cost is the inconvenience of buying it all at once, and finding a convenient place to stack it down until you need it.

I have read many reports from people in Wuhan and there is food in the grocery stores. Actually it seems like no currently effected area has a permanent food shortage - there is a run on the stores and then they are full after a restock. However, shopping requires you to leave your house so you will want to minimize it. I think people are over-focusing on food shopping because it feels actionable. You are right that there is almost no downside

If one becomes ill, he needs foods which he could eat without cooking and which are very nutritious. For around one month. One can't eat raw rice, but dry bananas are great.

Adam Zerner


Cabin fever is unnecessary.

According to the CDC the coronavirus is thought to spread similarly to how the common cold spreads: person-to-person spread, and contact with infected surfaces or objects. There are certainly ways to get out of the house without coming in close contact with other people and without coming into contact with surfaces that others have touched. For example, going for a walk or a bike ride. (In densely populated cities this will certainly be harder.)

Furthermore, socializing with friends who you trust shouldn't be too risky. From the CDC:

People are thought to be most contagious when they are most symptomatic (the sickest).
Some spread might be possible before people show symptoms; there have been reports of this occurring with this new coronavirus, but this is not thought to be the main way the virus spreads.

So then, if you know/trust that your friends are asymptomatic, and you trust that they are hygienic (wash their hands, wipe their counters, etc.), socializing with them shouldn't be too risky.

If it spreads like the common cold, how worried should I be about kissing people? Reason:

Kissing does not efficiently spread cold infection ... Of 16 susceptible recipients, only one became infected by a one or one-and-a-half minute kiss with an infectious donor.

Source: https://journals.sagepub.com/doi/pdf/10.1177/014556139407300906

3Adam Zerner
Interesting to hear that about the common cold. My first thought is that with the coronavirus, our risk tolerance is much lower, and even if the data point applied to the coronavirus as well, 1/16 still isn't great. So if it makes sense to take the precautions of washing your hands after touching surfaces that others have touched, it probably also makes sense to avoid kissing people. My second thought is that when you're kissing people it's probably going to be people you know personally and trust to be asymptomatic. But people can have the disease and be asymptomatic for weeks, so I'm not sure how much that helps.
and Yep, sounds right. :) Also right. Do you have any good pointers re: how much asymptomatic transfer there is? I've seen two things of note: 1. CDC director comment: https://www.cnn.com/asia/live-news/coronavirus-outbreak-02-13-20-intl-hnk/h_8d935a8b6df385aba0cbfdb30cd3aeac 1. Two cases mentioned here: https://www.businessinsider.com/coronavirus-asymptomatic-transmission-chinese-woman-relatives-2020-2 Part of me is surprised about how little evidence there is of asymptomatic transfer. Either it's not frequent, evidence is hard to gather, it's not worth mentioning/publishing after a certain point, something else?
2Adam Zerner
Not really, sorry. The source that comes to my mind is the CDC ("Symptoms may appear 2-14 days after exposure") but I also just generally recall various sources/people talking about it.
Asymptomatic transfer pointer. Saw in an ea Fb group claims ~ 15% household asymptomatic household transfer rate https://www.medrxiv.org/content/10.1101/2020.03.03.20028423v1?fbclid=IwAR14euEgPp3UvxBI2zSk-ZPCbbBzEV8JbyVVofxdgwqJDkRBoVKzREJdM4w

Does anyone have an update/ thoughts, on how safe it would be to take walks with asymptomatic friends one on one and keeping a distance of about 6 feet ?



Recommendation: cover the back of your smartphone in copper tape.

Reasoning: in addition to the reasoning for putting copper on all commonly touched surfaces, your phone is an especially good choice because of the "copper halo effect", in which copper ions move from copper surfaces to nearby surfaces (like, say, your hands), leaving them much less hospitable to microbes. [Edit: As MalcolmOcean points out, this mechanism for the halo effect isn't supported by the Wikipedia page below. I made a leap to this explanation without realizing it. That said, I do think that copper (and copper oxides) will get on your hands as a result of this tape, partly because I've seen my hands turning a bit blue.]


A downside is that your hands may turn slightly blue. [Also: See the comment below about uncertainty about how much copper you'll eat as a result of this; tldr: I don't know but I think it's probably fine]

[This is a signal boost for Lady Jade Beacham's response to Connor_Flexman, but the idea was originally introduced to me by James Payor]

palm rests of laptop are easy too.

Note that this can act as a Faraday cage around your phone and potentially reduce your reception.

With the fullback of my phone covered in copper I got ~0.2 Mbps on 4G. When I removed a 1 in.² on the upper left (where the antenna is on a Google pixel 3) it went up to 13 Mbps.

I assume having everything except for a small square covered is still pretty good, so I'm doing that.

Huh. This is quite important if true. Can anyone with a bit more physics/chemistry knowledge give an estimate for how long this will last on your hands, and how much coverage of your hands you will get? If this is a significant effect, it seems like a pretty useful piece of prep (copper on phones) that I am only just hearing about.

The halo effect (section on wikipedia) didn't seem to me to be about ions... I figured it was just like how if we're nearby & I'm less likely to get sick, then you're less likely to get sick, separate from my sickness having any effect on your immunity.

Yeah, you're right that I imputed a particular mechanism that isn't supported by the Wikipedia page - thanks for pointing that out. I do still think that the ions-getting-on-things mechanism is part of the story, mostly because the reduction sizes are really large. This could indicate either (a) that most microbes end up on surfaces first via touch surfaces, and spread from there, or (b) that copper ends up on nearby surfaces. Or some of both. In this particular case, though, I think it's quite likely (because I've seen my hands turn a bit blue) that in fact copper and copper oxides are getting on my hands as a result of the tape.

A thing I probably haven't thought enough about is, "how much this will impact your rate of copper ingestion, and is that very bad?" My guess is that this is less important than the effects on infectious disease; it seems like it would need to increase your copper consumption by 100x in order to produce major negative health effects (https://www.atsdr.cdc.gov/toxprofiles/tp132-c2.pdf). I may try to be virtuous and do a fermi on this later but also I'd welcome someone else trying to do it.

Edited to add:

The most obvious effect of having too much copper is ga

... (read more)
A bit more copper might actually be a good idea for people who also take zinc (see the zinc thread elsewhere in this post) as the body needs to keep both of these in some balance. Dangerous levels of copper seem highly unlikely just from touching but you should probably avoid lining your pots and pans: https://en.wikipedia.org/wiki/Copper_toxicity

I would much rather rinse a mobile phone regularly if it is water-proof (an increasing number is!) than use copper tape, although I would not use soap on the screen, to preserve its oleophobic properties; alternatively, if I were in a very susceptible group or if the virus were much more dangerous to me, I would find it more effective to put the phone in a plastic bag and either exchange it often or wash it as often as my own hands.

The thought process here is that copper tape cannot be applied to screens, which can end up very close to faces, but washing with soap is effective.

It is possible to both rinse your phone and put copper tape on it.

Another cost is that my hands smell like copper now.

Maybe we should put copper on our hand sanitizer bottles. But does it take effect quickly enough to matter here?



Advice: Apply lotion after washing your hands.

Reasoning: Heavy handwashing can dry out your hands, which can lead to cracks forming, which are more vulnerable to infection. You can fight this by applying lotion after washing your hands.

Sources: have experienced dry hands -> cuts personally, a dermatologist told me it was a vulnerability.

Related: CDC recommends washing with warm or cool water as opposed to hot, because hot water doesn't help more and is more likely to bother your skin. https://www.cdc.gov/handwashing/show-me-the-science-handwashing.html

A discussion / recommendation on handwashing versus sanitizer would be most welcome, I think. I have seen recommendations ranging from "always wash hands if possible, use sanitizer only if handwashing is not possible" to "use hand sanitizer unless your hands are visibly dirty, in which case wash them."

I am a bit concerned that applying lotion after handwashing is potentially a good way to re-contaminate your hands, unless you and everyone in your household is very careful about how you handle the lotion.

(I seemingly managed to give myself irritant contact

... (read more)
CDC advises alcohol based sanitizers at least in clinical settings, IFF your hands are visibly clean - since it's more effective in that case, and less drying. (Note: it does not help if you have actual bits of dirt on your hands.)

Their advice for healthcare settings is to prefer hand sanitizer, because it's better at killing germs, it doesn't dry your skin as much, and you're more likely to actually use it. https://www.cdc.gov/handhygiene/science/index.html

Their advice for community settings is to prefer soap and water, as far as I can tell because you're more likely to have stuff on your hands (grease, dirt), and because kids might drink it. https://www.cdc.gov/handwashing/show-me-the-science-hand-sanitizer.html

This coronavirus-specific page seems to treat them interchangeably. https://www.cdc.gov/coronavirus/2019-ncov/hcp/guidance-prevent-spread.html

A link here would be fantastic!
I've heard but have not researched that within the range of water temperature a human being can stand, the temperature isn't contributing anything to the anti-microbial effects. So colder water for more handwashing or less irritation might be free money.

There's also hand soap with build-in lotion: https://www.amazon.de/gp/product/B01G8NH5F0

Lots of products exist, but are you sure that it's as effective at killing germs, and keeping your hands clean?
Soap doesn't work by killing germs. It works by detaching them from your skin.
I thought this too, and then I read that coronavirus is an "enveloped virus" whose coating can actually be basically dissolved by soap & scrubbing: On reflection, I don't have a source I deeply trust for this. The quote above is from this tweet by a Johns Hopkins prof. Consider this a jumping off point for further investigation.
4Thomas Kwa
It looks like the lipid envelope is a feature of many viruses, including all influenza viruses: source; Wikipedia and the NIH corroborate.
Yes, and that's why putting lotion on seems obviously counter productive - it's keeping the skin moist.
The CDC recommends drying hands, because wet hands spread and receive microbes more easily. (Although that's microbes generally and they're not sure about disease-causing germs in particular). https://www.cdc.gov/handwashing/show-me-the-science-handwashing.html So I'd think that applying lotion and then, say, opening the bathroom door with lotiony hands will re-contaminate your hands. Doing it just before sitting at your desk for a while or going to bed might be a better time, so your hands can dry when you're not going to be walking around touching stuff.
I wonder about dryness and its effect on immune cells. Dryness can also kill certain immune cells, which can ultimately lead to a better environment for germs than if you had left the wound moist. My original source for this is a book on historical medicine that I can no longer remember, but a 20 minute literature check finds that modern wound care emphasizes keeping wounds moist (but not too moist, and not in all circumstances), both to prevent infection and promote faster healing: * Clinical and Financial Advantages of Moist Wound Management * Moisture and healing: beyond the jargon * Formation of the Scab and the Rate of Epithelization of Superficial Wounds in the Skin of the Young Domestic Pig * PREPARING THE WOUND BED 2003: FOCUS ON INFECTION AND INFLAMMATION I could imagine that handwashing is a similarly horseshoe shaped problem- too moist and you increase your hands' habitability for germs, too dry and you make it easier for germs to permeate your skin.
The German equivalent of Consumer Reports believes this to be the best hand soap product that's currently on the market in Germany in the class of products that aren't specifically antibacterial. For me that means there's no reason to believe this product is worth at keeping my hands clean. Using soap that's antibacterial seems to be a move that's bad for the commons as far as building up antibacterial resistance goes. Do you disagree there and think everyone should use antibacterial soap?



If the local case rate is not yet high enough to warrant quarantine, and you're hosting or attending events, then in addition to asking people to not come if they are sick or coughing, you also might want to implement fever screening.

Three studies of nCoV symptoms cited here found fever in 83%, 98%, and 98.6%. Studies are less precise on the exact timing of symptom manifestation, but fever appears to show up early. To screen people for fever, you need either an oral thermometer plus disposable probe covers, or a contactless infrared thermometer. A contactless thermometer is faster, but less reliable; if you use one, you will want to also have an oral thermometer plus probe covers to deal with false positives.

What temperatures should be used as cutoff when doing fever screening at events in the evening?

What's the risk in sharing an oral thermometer/how do you sterilize it effectively?

They make non-contact digital thermometers now. You could get one of those. Point and shoot.
You put a disposable cover over on it, eg these, which covers the part that goes in peoples' mouths. So the main risk is that everyone is touching the same object with their hands. You can mitigate that by also having them wash their hands or use hand sanitizer afterwards.



For me personally, self quarantine seems pretty unnecessary at this point, but I would act differently if I were in a different age group. Given the below death rates I would self quarantine if I were over 40. I would like to note I expect these death rates to be somewhat high because they are largely based on confirmed cases, which I expect to be disproportionately the worse cases that ended up in hospitals.

There was one case of Covid-19 in Solano county (CA) that couldn't be traced directly to travelers, which indicates community spread may be happening and Covid-19 may be spreading in the bay area.

Age  Death Rate
80+ years old  14.8%
70-79 years old 8.0% 
60-69 years old 3.6% 
 50-59 years old 1.3%
 40-49 years old0.4% 
 30-39 years old0.2% 
 20-29 years old0.2% 
10-19 years old 0.2% 
 0-9 years oldno fatalities 

Given the below death rates

Note that while your personal survival is quite important, getting infected and surviving can have quite awful effects. We don't know what the long-term effects are like yet (because we haven't hit the long-term yet), but I won't be surprised if post-viral fatigue is common.

Being ill is also unpleasant, and you become a risk to your community, and especially any elderly people in your community.

At least there is some evidence that the lung fibrosis that you were seeing in a lot of SARS survivors is not happening at nearly the same level.
Yeah, It's true we don't know the long term effects yet and being ill is unpleasant. I'm taking the minor precautions of not going to large public spaces (BART, Grocery Stores, Gyms) for a while.

These numbers are applicable when there are hospital beds and equipment and staff to treat the 20%ish of severe cases. When the hospitals get overwhelmed, the fatality rates will go up. By how much? I have a guess broken down by age here.

Note that there has been a second confirmed case of community transmission in the Bay Area. WaPo link


Great table to offer. Might be good to also update on some related state. Males seem twice as likely as females to contract the infection (not positive here if that also scales with age or not)

Also, those with preexisting condition (heart, lung, other immune system taxing states) are also more likely to suffer more, and be among those dying than those who are generally healthy.

I think there was al