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"Everyone knows" - a scary statement - that you get "a cold" from being cold. Now it seems to be a fact that you don't, because you get a cold from a (rhino)virus, not from the temperature.

But is there any correlation between temperature and disease?

I've seen claims that "cold lowers your immune system", and stuff like that, but no real evidence. As soon as you look into scientific research about this, you get claims that the correlation is not causation, because in the winter people spend more time inside (close to one another) for instance. (See for instance this article)

On the other hand - and I know this is a really bad form of reasoning -- I think if I'd go outside in the freezing cold wearing nothing but some summer pants, I'd not come out of that after a couple of hours like a happy camper. Is this non-sense, or is there some correlation between being cold (or even undercooled?) and disease? If so, how does this work?

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    Another potential correlation between cold weather an getting ill is that when it's cold out we spend more time cooped up inside and in the company of others, thereby making the transmission of a cold virus more likely. Feb 26, 2011 at 0:33
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    HI i'm a biomed student, and I seem to remember that some time ago, a tutor explained that it had to do with the fact that we get runny noses in cold temperatures and therefore we 'catch' more viruses through this mucosa...? Steph Mar 5, 2011 at 20:26
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    "Everyone knows" - I think it may be slightly culture-dependent. Coming from the UK, no-one seemed to be particularly bothered. But in Italy, you get people closing the windows in summer because of 'drafts' that are going to make them ill...
    – Benjol
    May 5, 2011 at 6:38
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    @Benjol Oh God, tell me about it. This devilish 'draft' deserves a question of its own! May 30, 2012 at 16:04
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    A precise way to formulate this question is "is exposure to a cold environment a risk factor in developing the common cold?" - a positive answer implying that avoiding being in cold places lowers the risk.
    – RomanSt
    Jul 5, 2014 at 11:12

4 Answers 4

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Aside from the effect of cold temperatures on the human body, it's also important to consider the effect of cold temperatures on the virus.

One study found reduced virus infectivity at 37 degrees celcius while it was stable at 6 and 23 degrees.

And while we're at it, there's even more data on the flu. Quite a few studies found that "cold temperatures and low relative humidity are favorable to the spread of influenza virus."

So humidity is also important, as well as the interaction between humidity and temperature:

there seems to be some general indication that minimal survival for both lipid-enveloped [e.g. influenza] and non-lipid-enveloped viruses [e.g. rhinoviruses] occurs at an intermediate RH [relative humidity] of 40–70% (Arundel et al. 1986). Also, it is important to note that temperature and RH will always interact to affect the survival of airborne viruses in aerosols.

[Edit: In my initial answer I suggested that being cold doesn't make a difference to you. That's not quite true. It does seem to increase susceptibility to infection, though of course the point is that you do need to be exposed to a virus; you don't get a cold just from being cold.]

While temperature may have an effect on your susceptibility to infection, it also has an effect on the survival of the virus outside your body. They prefer colder (less humid) environments. This does mean you're more likely to catch a cold when it's cold, because the virus is more likely to survive and be transmitted.

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    That is good point!
    – Nanne
    Feb 26, 2011 at 8:02
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    How many times have you heard mother's tell their kids that they need to put a sweater on, or they will catch a cold while playing outside, even if they were just playing in the front yard. I was just pointing out that if you are just in a cold environment without contact with others that might already be sick, you aren't likely to increase your risk of infection.
    – Ustice
    Mar 2, 2011 at 13:38
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    Had the possible correlation crowded rooms/better virus spread in the winter been discussed in the study?
    – Philip
    Mar 5, 2011 at 22:24
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    I’m wary of the virus’ relation to temperatures (= I think it’s wrong). No matter how cold it is outside, and no matter how little clothing you wear, your body temperature will never be anywhere near 23°C, let alone 6°C. And I also don’t see how these temperatures influence the virus’ spread. Humidity – yes. Cold weather? No. If the virus didn’t survive (substantially) warmer climates, it couldn’t survive in our bodies. In summary, I’m pretty sure the answer is wrong. Mar 7, 2011 at 18:40
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    @Konrad: Body temperature is irrelevant to the viruses ability to survive outside the body. Also, there's data supporting the conclusion. Your certainty that it's wrong doesn't change the results of the research. How is it wrong? Mar 8, 2011 at 21:49
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From a 2007 review (Exposure to cold and respiratory tract infections by Mourtzoukou & Falagas):

… most of the available evidence from laboratory and clinical studies suggests that inhaled cold air, cooling of the body surface and cold stress induced by lowering the core body temperature cause pathophysiological responses such as vasoconstriction in the respiratory tract mucosa and suppression of immune responses, which are responsible for increased susceptibility to infections.

(Emphasis mine.)

Two things are worth noting:

  • This review partly contradicts the conclusion in Solus’ answer, that “being cold doesn't seem to make a difference to you”. According to the review, it’s does. However, Solus’ answer is mainly concerned with influenza which is somewhat different from the rhinovirus so while his answer may actually be true, it almost certainly doesn’t apply to the common cold.

  • This isn’t undisputed – there is also some evidence to other causes (notably Eccles (2002) and Brenner & al. (1999)). But most of the evidence points this way. Furthermore, the study by Eccles actually proposes a mechanism which isn’t that much different from the one above.

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  • Ooh, interesting. I do disagree with you "other way round", as it still is so that the temperature does effect the virusses, isn't it? It might also be a good thing to add that the described "respiratory tract infections" do indeed include the cold ('upper') (and pneumonia, 'lower'). And, while you say it isn't disputed, how about ncbi.nlm.nih.gov/pubmed/12357708 or other sources that do actually dispute it? *I'm no saying this is false, au contraire, but maybe you could expand a bit? +1 at least for interesting article!
    – Nanne
    Mar 9, 2011 at 10:05
  • @Nanne Hmm, my answer already lists this paper (and one other). Perhaps you haven’t read my updated answer yet. Furthermore, their proposed mechanism is actually quite similar, it just assumes a prior infection. As for “it still is the temperature does effect the virusses, isn't it?”: again, see the updated answer. I think this only applies to influenza, not rhinovirus. And as I’ve explained in a comment below Solus’ answer, I even have some doubts here. Mar 9, 2011 at 10:12
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    @Nanne That’s actually not what I meant; my answer didn’t intend to mention the connection between temperature and virii at all. What I see contradicted is Solus’ claim that “being cold doesn’t seem to make a difference to you” (I’ll edit to make this clearer). As for my comment below Solus’ answer, I’d like to know what you find unclear: I don’t have to provide a basis for my assertion, the onus is on the other side to substantiate their claim. Furthermore, my claim follows from logic: the virus flourishes at 37°C in the body, so why not also outside? Why would it need colder temperatures? Mar 9, 2011 at 10:55
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    @Nanne: yes. In fact I’m not convinced in the case of influenza either. Just to clear matters up: I do acknowledge that temperature influences virus survivability. But only if it surpasses our body temperature (otherwise it couldn’t flourish in us, but fever does kill virus infections). And I do acknowledge that a virus’ optimal working temperature is below our body temperature but this is irrelevant for infectivity / spread since aerosol borne virii are not active. They need a host cell to become active. A virus in itself has no metabolic activity. Mar 9, 2011 at 11:25
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    @Nanne Duh. I’ve just now read the abstract of the study Solus linked to. They explain that the temperature doesn’t directly act on the virus at all – rather, in warmer temperatures the aerosol is evaporated. This would of course inhibit spread. This clears it up for me. Mar 9, 2011 at 11:29
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Latest study confirms that the chances increase due to a variety of factors diminishing immune response, at least in mouse cells:

Temperature-dependent innate defense against the common cold virus limits viral replication at warm temperature in mouse airway cells (Ellen F. Foxman, doi: 10.1073/pnas.1411030112)

... To gain insight into the mechanism of temperature-dependent growth, we compared the transcriptional response of primary mouse airway epithelial cells infected with rhinovirus at 33 °C vs. 37 °C. Mouse airway cells infected with mouse-adapted rhinovirus 1B exhibited a striking enrichment in expression of antiviral defense response genes at 37 °C relative to 33 °C, which correlated with significantly higher expression levels of type I and type III IFN genes and IFN-stimulated genes (ISGs) at 37 °C. Temperature-dependent IFN induction in response to rhinovirus was dependent on the MAVS protein, a key signaling adaptor of the RIG-I–like receptors (RLRs). Stimulation of primary airway cells with the synthetic RLR ligand poly I:C led to greater IFN induction at 37 °C relative to 33 °C at early time points poststimulation and to a sustained increase in the induction of ISGs at 37 °C relative to 33 °C. Recombinant type I IFN also stimulated more robust induction of ISGs at 37 °C than at 33 °C. Genetic deficiency of MAVS or the type I IFN receptor in infected airway cells permitted higher levels of viral replication, particularly at 37 °C, and partially rescued the temperature-dependent growth phenotype. These findings demonstrate that in mouse airway cells, rhinovirus replicates preferentially at nasal cavity temperature due, in part, to a less efficient antiviral defense response of infected cells at cool temperature.

Quoting one of the study authors (Akiko Iwasaki):

"Altogether," she added, "these temperature effects can result in an 100-fold difference in the level of cold virus" at 33C compared with 37C after three days - enough to turn an asymptomatic viral population into sneezing, runny-nosed misery.

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    In my opinion this should be higher up in the answers.
    – masfenix
    Feb 23, 2015 at 1:31
  • @masfenix it's a lot newer than the accepted answer
    – Celeritas
    Jan 23, 2017 at 0:31
  • @user5341 Thanks bro! I deleted my comment, you can delete your response! Enjoy an upvote for the help! Feb 4, 2017 at 1:23
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The straight dope discussed this. It made the following points:

  • The cold, wet feet, etc., don't make you more susceptible to the common cold.
  • If anything, long stretches of cold temps mean you'll catch fewer colds, presumably because the germs die off
  • We don't have indisputable evidence that winter is "cold season."
  • Winter is flu season, but not always.
  • Respiratory infections, setting aside colds and flu, seem to be more common in winter--but some think that's because of misdiagnosis (the article suggests that cold stress may be misdiagnosed as a cold)
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    Interesting, too bad that link doesn't include too much sources. One of the links that @Solus provided claims that in colder temperatures ar better for some germs?
    – Nanne
    Mar 5, 2011 at 10:02
  • @Nanne: As far as I could tell, Solus's link didn't discuss cold germs. It did discuss influenza though. The straight dope seems to contradict this though: "during major outbreaks the winter months typically bring an equally sharp upward spike in flu in all parts of the country. Sure, Chicago gets a little brisk in the winter. But L.A.?"
    – Casebash
    Mar 5, 2011 at 10:39
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    I was referring to the link that the quote was from, that specifies rhinovirusses, doesn't it? And I'm not familiar with the temperature in LA, but a random google seems to imply that it is below 23 celcius?
    – Nanne
    Mar 5, 2011 at 10:49

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