STUDIES ON PAIN. OBSERVATIONS ON PAIN DUE TO LOCAL COOLING AND ON FACTORS INVOLVED IN THE “COLD PRESSOR” EFFECT

Abstract

CONCLUSIONSPain due to local cooling is altogether separate from the sensation of cold itself. It is apparently mediated through small, non-myelinated fibers of class C. Its intensity, however, depends directly upon the degree of cooling. The stimulus re- quired for the production of "cold pain" may be found in the thermal gradient in the tissues of the immersed hand. It is possible that this stimu- lus brings about a painful vasospasm in the part. Relaxation of this local vasospasm may occur as the thermal gradient is decreased, thus accounting for " adaptation ". It appears that the "cold pressor" effect is a meaure of reaction to pain.