Cold exposure and immune function.

The influence of cold exposure on immune function is reviewed. Data obtained mainly on small mammals suggest that the acute effect of severe chilling is a suppression of several cellular and humoral components of the immune response, including a decrease of lymphocyte proliferation, a down-regulation of the immune cascade, a reduction of natural killer (NK) cell count, cytolytic activity, activation of complement, and the induction of heat shock proteins. However, adaptation to a given cold stimulus appears to develop over the course of 2-3 weeks. Further work is needed to examine interactions between cold exposure and exercise, and to determine whether the disturbances of immune response are sufficient to impair immunosurveillance in human subjects.