Does being cold give you a cold?

by Gillian Mayman on October 29, 2012

An illustrated guide to parenting with science.

The fall and spring seasons always create contentious relationships between my kids and their teachers. The problem is that the teachers insist that my kids wear coats when they go outside, even if they enjoy the chill in the air.

The teachers think that being cold means getting a cold.

Benjamin Franklin argued against this idea in the 18th century. He observed that sailors were constantly wearing wet clothing in cold weather but still remained healthy. He concluded that “People often catch cold from one another when shut up together in small close rooms, coaches, &c. and when sitting near and conversing so as to breathe in each other’s transpiration.”

But is this true? After all, Franklin posited this before the existence of viruses was known.

It is surprisingly difficult to find any experimental evidence that reliably shows that exposure to cold weather either causes colds or does not.

The National Institutes of Health says:

There is no experimental evidence  that exposure to cold temperatures  increases the chances that you will  get a cold.

In the review article, “Exposure to cold and respiratory tract infections,” E. G. Mourtzoukou and M. E. Falagas explore the scientific evidence for the common understanding that exposure to cold temperatures can cause a person to become sick with a cold.

They found ONLY ONE research paper with any experimental evidence to support the idea that being cold gives you a cold.

In this study, 180 college students were randomly separated into two groups. The first group of 90 students had their feet placed in a bowl of 50 degree Fahrenheit (10 Celsius) water for 20 minutes. The other group of 90 students kept their socks and shoes on and placed their feet in an empty bowl for 20 minutes. The researchers found that within 4-5 days, cold symptoms appeared around 10% more often in the students who had their feet chilled.

The study has a few problems. The largest problem is that it was not blind. That is, the people who had their feet chilled, knew that their feet were being chilled (of course). Even worse, the cold symptoms of the students were self-reported. The students kept daily journals after having their feet chilled (or not) and wrote down any cold-like symptoms that they experienced. The placebo effect is well studied and researchers know that simply thinking that something has happened which may cause an effect, can actually cause a real effect.

There are many studies that show there is no effect between exposure to coldness and getting a cold. But these are problematic as well. Most of the studies are from the mid-20th century. They were conducted primarily through dripping infected mucus into the noses of the research subjects along with being placed in a cold room or water. The primary concern with these studies is that having virus-laden snot dripped into your nose is not the natural way of contracting a cold. This does not mirror the real world closely enough and it is difficult for some people to take these results as conclusive.

Science and medicine are full of uncertainties. When the evidence is inconclusive, you are left to come to your own decisions based on what you see is the best evidence available.

For me, I agree with Ben Franklin. But I wish I had a stronger argument to convince the school that my kids don’t really need to wear coats if they’re not cold.

P.S.

The subject of why colds happen more often during cold weather seasons is extremely complex. If you would like more information on this topic, I recommend a paper by Yusuf et al. on meteorological events and the epidemiology of RSV (RSV is one type of virus which causes cold-like symptoms).