LOCAL SWEAT GLAND ACTIVITY DUE TO DIRECT EFFECTS OF RADIANT HEAT

Abstract

Using a method designed to investigate activity of individual sweat glands the sweating responses to locally applied radiant heat were studied. When the temps. at the skin surface were rapidly elevated to high levels (39-45[degree] C), large dark sweat spots appeared in the heated area, indicating excessive sweat responses by the individual glands. These spots contrasted sharply in size with those induced by normal reflex stimulation. A definite threshold temp. appears to exist, above which a direct response to local heat may occur and below which it does not occur. This threshold appears to lie within a rather wide range of temps. and the range of variation does not appear significantly different in summer and winter. Pharmacologic evidence is presented to suggest that the profuse sweating response of individual glands to extreme temps. is a direct one in contrast to the usually diffuse reflex response.