ABSTRACT
From the earliest Registrar General’s statistics and epidemiological studies in the UK an association has been established between cold ambient temperatures and respiratory illnesses. The invariable winter rise in the incidence of respiratory diseases such as bronchitis and bronchopneumonia is ascribed to the adverse effects of cold magnified by atmospheric pollution [Wright and Wright, 1945]. Cold conditions per se are not likely to result in respiratory infections in the absence of respiratory pathogens, as for example shown by the study on the island of Spitzbergen where throughout a severely cold winter no common colds or respiratory infections occurred until the arrival of the first ship at the end of the winter [Tyrrell, 1965]. However, a marked reduction in the temperature of the respiratory tract can increase susceptibility to pathogens by affecting the muco-ciliary defences and by initiating local inflammation.
