The common cold is a mild self-limiting illness usually confined to the upper respiratory tract ¹. The disease is self-diagnosed from a range of symptoms such as nasal stuffiness, sneezing, throat irritation and mild fever ². There is a common folklore that associates the development of symptoms of common cold with exposure to a cold environment, and that the onset of a cold is a direct result of wet clothes, feet and hair ³. Throughout the clinical literature of the last three hundred years there have been many reports that acute cooling of the body surface causes the onset of symptoms of common cold, and historically it has been generally accepted that acute exposure to cold is a direct cause of these symptoms ^{4, 5}.

However, studies involving inoculation of cold viruses into the nose and periods of cold exposure have failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses ^6-8. Although modern textbooks of virology dismiss any cause-and-effect relationship between cold exposure and common cold as erroneous folklore⁹, the belief is so widespread and longstanding it is difficult to completely dismiss this idea as having no validity.

In 1919 Mudd and Grant studied the reactions of the nasal mucosa in response to chilling the body surface and showed that cooling the body surface causes a reflex vasoconstriction of blood vessels in the nose and a decrease in temperature of the mucous membrane ¹⁰. They speculated that this reflex vasoconstriction of the airway epithelium could decrease resistance to infection and allow bacterial infection of the tonsils ¹⁰. Some years later Sir Christopher Andrewes suggested that exposure to a cold environment may trigger the development of a cold but only in people who are carrying the latent cold virus ⁶. Eccles developed these early observations by proposing a hypothesis that acute cooling of the body surface causes a reflex vasoconstriction in the nose and upper airways, and this vasoconstrictor response may inhibit respiratory defence and cause the onset of common cold symptoms by converting an asymptomatic viral infection (sub-clinical infection) into a symptomatic viral infection (clinical infection) ¹¹. The novel idea in this hypothesis was that when common cold viruses are circulating in the community a proportion of those infected will have sub-clinical infections, and that when any of this sub-group are exposed to chilling of the body surface this could aid conversion of a sub-clinical infection to a clinical infection. This study was aimed at testing this hypothesis, by studying the onset of common cold symptoms after acute chilling of healthy asymptomatic subjects, during the winter, when common cold viruses are circulating in the community.

An abstract of the results of the study we published in 2005 is provided after the references. More research is needed to confirm our preliminary findings that chilling can induce colds.

1.Heikkinen T, Jarvinen A. The common cold. Lancet 2003;361(9351):51-9.

2. Johnston S, Holgate S. Epidemiology of viral respiratory infections. In: Myint S, Taylor-Robinson D, editors. Viral and other infections of the human respiratory tract. London: Chapman & Hall; 1996. p. 1-38.

3. Helman CG. "Feed a cold, starve a fever" Folk models of infection in an English suburban community, and their relation to medical treatment. Cul Med Psychiatry 1978;2:107-137.

4.Lower R. De Catarrhis. 1963 ed. London: Dawsons of Pall Mall; 1672.

5.Mackenzie M. Diseases of the throat and nose. London: J. & A. Churchill; 1884.

6.Andrewes C. The Common Cold. New York: Norton; 1965.

7. Dowling HF, Jackson GG, Spiesman IG, Inouye T. Transmission of the common cold to volunters under controlled conditions. II. The effect of chilling of the subject upon susceptibility. American Journal of Hygiene 1958;66:59-65.

8. Douglas RGJ, Lindgren KM, Couch RB. Exposure to cold environment and rhinovirus common cold. Failure to demonstrate effect. New England Medical Journal 1968;279:742-747.

9. White DO, Brown L. Respiratory viruses. In: Gronoff A, Webser R, editors. Encyclopedia of virology. San Diego: Academic Press; 1999.

10. Mudd S, Grant SB. Reactions to chilling of the body surface. Experimental study of a possible mechanism for the excitation of infections of the pharynx and tonsils. Journal of Medical research 1919;40:53-101.

11. Eccles R. Acute cooling of the body surface and the common cold. Rhinology 2002;40(3):109-14.

Abstract of the results of the study on chilling and colds

Johnson, C. and R. Eccles (2005). "Acute cooling of the feet and the onset of common cold symptoms." Fam Pract 22(6): 608-13.

BACKGROUND: There is a common folklore that chilling of the body surface causes the development of common cold symptoms, but previous clinical research has failed to demonstrate any effect of cold exposure on susceptibility to infection with common cold viruses. OBJECTIVE: This study will test the hypothesis that acute cooling of the feet causes the onset of common cold symptoms. METHODS: 180 healthy subjects were randomized to receive either a foot chill or control procedure. All subjects were asked to score common cold symptoms, before and immediately after the procedures, and twice a day for 4/5 days. RESULTS: 13/90 subjects who were chilled reported they were suffering from a cold in the 4/5 days after the procedure compared to 5/90 control subjects (P=0.047). There was no evidence that chilling caused any acute change in symptom scores (P=0.62). Mean total symptom score for days 1-4 following chilling was 5.16 (+/-5.63 s.d. n=87) compared to a score of 2.89 (+/-3.39 s.d. n=88) in the control group (P=0.013). The subjects who reported that they developed a cold (n=18) reported that they suffered from significantly more colds each year (P=0.007) compared to those subjects who did not develop a cold (n=162). CONCLUSION: Acute chilling of the feet causes the onset of common cold symptoms in around 10% of subjects who are chilled. Further studies are needed to determine the relationship of symptom generation to any respiratory infection.