My understanding is that colds come from bacteria, the flu from a virus. So, what is the foundation of the belief/old wives tale that a person will “catch their death of cold” if they go outside in winter with their hair wet? To the best of my knowledge, wet hair doesn’t attract germs…
Colds are spread by someone sneezing, contact with a person with a cold or coming in contact with an object touched by the diseased person. Getting cold is not a contributing factor.
Right, my question was, why is this such a widespread belief? I have heard this countless times from grandparents and other seniors, but what really puzzles me is younger folks, like in their 20s and 30s who actually believe this as well…
I don’t think this exactly answers your question but here is Cecil’s take on being cold = getting a cold.
i think the deal is the fact that you lose what? something like 80% of your body heat through the top of your head?
IANAD, so those more learned, please step in.
having a wet head might very likely accelerate that process, getting you much colder than is warranted and therefore feeding the old wives’ tale about contracting a cold in the process.
i thought the losing heat through your head thing was a bunch of hooey - until the divemaster plonked a stocking cap on my head one night while we were sitting on the couch watching tv. i’d been complaining about the house being cold, and he’d adjusted the thermostat twice for me.
the third time i complained, out came the stocking cap. it worked. 
I thought I had read something about a difference between an actual cold (viral infection) and “cold effects,” congestion caused by exposure to cold air.
Being cold, especially if you are not accustomed to it, can stress you physically. Having wet hair can result in rapid heat loss on cold days. Physical stressors in general seem to impact the immune system, IE you are probably more susceptible to colds (or diseases in general) if worn out and tired. Not a solid link by any means, but keeping warm probably puts less stress on your immune system than being cold.
This would obviously not apply to people who are acclimated to cold weather like Inuits. Patagonians, Tibetans etc. In fact I’ve heard that warm weather can excerbate disease conditions for these people.
This is my take on it. It’s not being in the cold, or having wet hair, it is feeling cold, and perhaps even thinking you are feeling cold or thinking you are more likely to get sick that somehow suppresses the immune system.
I think it is called a “cold” because it usuually happens when people are gathered together for warmth, and therore share germs.
As Cecil notes, being cold may make your nose run, causing you to wipe or blow it more frequently. It’s possible that if you are around someone with the cold virus, you may be more likely to transfer it from your hands to your nose while wiping or blowing, where it may infect you much more easily.
And it seems possible that this could be exacerbated by the other things mentioned, such as being closed in with other people, lower immune response due to cold stress, etc.
I love this. There’s no evidence that cold causes colds (see The Great Master on this), but people are still weighing in with hypotheses on why they do. In the field of science education, there is a large research area referred to as Misconception studies. Anyone interested in the phenomenon should spend some time with it (Google misconception research). The OP’s question is certainly excellent, and to the best of my knowledge, the answer is not known. But some misconceptions are pretty clear as to their origins.
E.g. - A common misconception is this: We breathe in oxygen and breathe out carbon dioxide. Many people believe this to be true. But the fact is that we breathe in air and we breathe out air. The air we inhale has a bit less CO2 and a bit more O2 than the air we exhale - by only a couple of percent. If this were not true, you couldn’t do much good with artificial respiration, could you? Where did this misconception come from? Probably, it can be traced back to elementary teachers making an attempt at explaining how animals and plants rely on each other in their use of the atmosphere. It’s a gross oversimplification, but it’s a beginning at teaching the concept of interdependence. Unfortunately, it usually goes only that far and no farther in schools, so we now have teachers telling their children that and believing it’s true, without being aware of the nature of the misconception inherent in that assertion. But we all hold many of these beliefs for no other reason that we heard them, were taught them, or just made them up. Along these lines, I just saw a bumper sticker that says, “Don’t believe everything you think.”
xo, C.
Well, it killed an American president. William Henry Harrison gave a long speech in a cold rainy downpour, caught a cold, which turned into pneumonia, and died. At least that’s the story.
Even in today’s enlightened age, those points are mentioned in the same sentence as if to imply it was cause and effect.
Untrue. Both colds and influenza are caused by viruses.
Will you catch a cold/flu/pneumonia? Probably not.
Are you putting yourself at risk to develop a mild case of hypothermia? You betcha - as it’s already been mentioned, you lose a substantial amount of heat through your head, and wet hair will speed up the heat loss quite nicely.
So you might not end up with a cold, per se, but you’re still going to end up feeling a whole lot more miserable than you’d have felt if you’d just listened to your grandmother instead of rushing off like the impatient know-it-all youngster you are. Wear a hat! Dry your hair! And would it kill you to call once in a while?
(Yes, they’re naggers and they worry about you dying in a million impossible ways… but there’s usually a small grain of truth hiding under all the kvetching - how else do you explain the magical powers of Bubbie’s chicken soup?)
I hope this thread isn’t too old to resurrect, but I just saw this:
U.S. study shows why winter is ‘flu season’
which is reporting a study that shows that the flu virus has a coating that may protect it more in colder weather, allowing it to survive and pass from person to person more frequently.
So winter may actually be the flu season, and the reason actually is the cold, but not because of the effect on us, but because of the effect on the virus.