How many have you experience get common cold after acute exposure to cold or getting wet in the rain. For centuries there has been an idea across many parts of the world that you will develop a cold if you are exposed to low temperatures, particularly if you get wet as well. Our mom, grandmother used to warn us above these ideas. So how much is true about grandmother warning?
In one study researchers found that acute chilling of the feet causes the onset of common cold symptoms in around 10% of subjects who are chilled. Studies in Germany and Argentina have found a higher incidence of colds in the winter, while in warmer countries such as Guinea, Malaysia and the Gambia peaks have been found during the rainy season. We could relate from these studies that cold or wet weather something to do with common cold.
For this to make any sense there needs to be a mechanism by which getting chilled feet, or wet hair, could give you a common cold. One theory is that when your body gets chilled the blood vessels in the nose and throat constrict. There will be less blood supply so less white blood cell which is needed to fight against the microorganism including common cold virus. If fewer white blood cells reach the nose and throat your defenses against a cold virus are lowered for a short time. Also if the environment is cold air (which is less humid than warm summer air) can dry out the mucus lining of your nasal passages, making it easier for viruses to get in and make you sick.
Moreover if you get wet by rain or immediately exposure to ultra-cold weather your body is in stress and certainly affect your immune system. So, there might some truth about grandmother advice not to go out in rainy day or expose to cold weather.
Source: www.bbc.com
http://fampra.oxfordjournals.org/content/22/6/608.short
http://www.huffingtonpost.com/2015/02/25/cold-wet-hair-germs_n_6739144.html
