"You'll catch your death of cold going out like that!" We've all heard the old wives tale that going out with wet hair/ no coat/ no umbrella will give us a chill and from this we are likely a nasty cold. But is there any scientific evidence linking getting cold with getting ill? The answer to this is no, although plenty of people have tried to prove a link between temperature and the common cold over the years.
It all started with Louis Pasteur who, in 1878, observed that chickens are immune to anthrax (which is a bacterium rather the cold virus but its the same principle). He believed that the high body temperature of a chicken (around 105 degrees Fahrenheit) was somehow preventing it from getting ill so he stuck poor Monsieur Poulet in cold water and managed to give him anthrax. Sadly, the chicken died but Pasteur had proved his point.
The last 100 years have seen some slightly better experiments to investigate the link between getting chilly and catching a rhinovirus (that's the common cold virus) infection. In the 1950s, scientists compared men sitting in a warm room wearing socks and underwear (warm enclosed space, semi-naked men, a few hours...can't have smelt nice) with men in a freezer (they got gloves, hats and coats). They found that they all caught colds at the same rates.
A similar experiment, in 1968, chilled men in cold baths before dripping the rhinovirus into their noses. Once again, un-chilled and chilled people got colds at the same rates. In fact, a more recent piece of research suggests that cold temperature actually stimulates the immune system, priming it for future infections and better protecting you against the winter sniffles.
The general consensus appears to be that contact with an infected individual- particularly their hands - is a much more important risk factor for getting a cold than cold weather. In fact, the most important cold virus (rhinovirus) prefers the spring and the autumn rather than the winter - it likes humidity not cold. The reason we tend to get more colds in the winter is due to us staying in and being in much closer contact with each other. The only way to get a cold is from an infected person - we're much more likely to come in contact with one when sitting in enclosed spaces with the air conditioning blowing our sneezed up virus around the place.
Another study comparing asthmatics with healthy volunteers found that the group with the impaired lung function did not get any more colds than the healthy group. Most healthy people who were exposed got ill, although the asthmatics got slightly more serious infections on the whole. In all, cold weather, fatigue, and sleep deprivation have not been shown to increase your risk of getting a cold. If you're going to get one, then not much is going to help you.
So why is the research still going on? The thing is, these studies haven't completely answered the original question. Pouring virus into peoples noses isn't exactly what happens in real life. Perhaps overall health and body temperature effect whether or not you get a cold after exposure to much lower amounts of virus than were used in these studies. Who nose?
