Most people think it is common sense that cold weather causes more colds. And traditional Chinese medicine is even more emphatic about this, categorizing many respiratory illnesses as wind-borne or cold-borne. And who didn’t grow up hearing their mother tell them to “bundle up or you’ll catch a cold”?

But really, there isn’t strong evidence that cold temperatures by itself cause more colds. In fact, there is good evidence that cold weather does not cause the common cold. Yes, it does seem intuitive that cold weather may lower your immune system, and some studies do suggest that. And it makes sense that since a low-grade fever can increase neutrophil response, that a cold temperature would do the reverse and slow those infection-fighting cells. But the fact remains that the best studies which specifically separated patients into two groups (a cold group and then a normal temperature group), then exposed them to the common cold virus, showed no change in infections in the cold-exposed group. There’s also a pretty good review of the medical evidence at Wikipedia, along with sources of relevant articles. I included one link at the end of this post which details one of the more famous articles.

One likely reason that people think being cold causes a cold is that the rhinovirus always flares up during the winter months. Also, in winter people are huddled together in close quarters, so they expose others to the virus via respiratory particles. So, colds are always more frequent in the winter — but not because of the cold temperature itself on your body.

This is an interesting academic debate which is far from agreed upon by researchers, and honestly I am still a bit skeptical and would love to see other studies, especially from Chinese journals. No matter what you believe, common sense still prevails — I have no plans to start jogging naked through the winter streets. The American Academy of Pediatrics, which agrees with the American Lung Association that “cold weather does not cause colds or flu”, has a nice handout on winter safety tips for children.

Article: UNDERSTANDING OF VIRAL RESPIRATORY ILLNESSES PROVIDED BY EXPERIMENTS IN VOLUNTEERS.