SOME OBSERVATIONS ON GENERAL SKIN TEMPERATURE RESPONSES TO LOCAL HEATING OF HUMAN SUBJECTS IN A COLD ENVIRONMENT

Abstract

Studies are reported of skin temperature measurements with 9 normal [male] subjects exposed to local heating while maintained in a constant environment at a cold temp. Local heating by immersion in water at 43 to 44 [degree]C. produces a larger rise in skin temp. in all locations except the back when the 2 forearms are immersed than when the legs, up to the knee, are immersed. Immersion of one leg alone does not produce a significant general skin temp. rise under these conditions. Immersion of both forearms with circulation occluded by pressure cuffs above the elbow results in no sustained rise in general skin temp. The sensation of warmth in the forearms and hands is retained in spite of vascular occlusion. The subjective feeling of general bodily warmth is proportional to the general skin temp. rise. Except for the feet and the hands the skin temp. rise following local heating is temporary in spite of continuous application. The rectal temp. remains constant within 0.2[degree]C. in subjects in the cold room at 16.7[degree]C. with or without application of local heat. There is a tendency for rectal temp. to fall slightly upon local heating. Assuming that skin temp. changes reflect alterations in blood flow through the surface tissues it is deduced that prolonged vasodilatation due to adequate local heating is probably mediated by some type of central mechanism. This is in agreement with earlier suggestions of the same sort. However, it is not believed possible that general body temp. can determine the effect because vasodilatation can occur with a falling rectal temp.