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.