Effect of sweating and changes in blood flow on heating of human skin.

Abstract

Summary and Conclusions1. Acetylcho-line-induced sweating decreases and atropine-induced inhibition of sweating increases heating effects of radiated heat energy. Increased blood content of tissues has a slight effect and increased blood flow a more pronounced effect on lowering the heating effect. 2. The effects of sweating appear to be due partly to vaporization of water at the skin surface and partly to a change in the thermal characteristics of the skin itself. 3. Increased blood flow through the skin raises the temperature and therewith increases the heating effects of low-energy, short-time radiation. However, the thermal characteristics of the skin are changed in a way to combat these heating effects. Therefore, the harmful effects of high energy and long term radiation are decreased. 4. Pain threshold is frequently measured as temperature elevation or as reaction time, and then it is markedly affected by changes in blood flow and rate of sweating. However, if it is studied in terms of tissue tempe...