Protection of Aircrews from High Temperatures;use of a Water-Cooled Garment for Heat Balance Studies in Man.

摘要

A water-cooled suit was developed for use as a direct calorimeter with error of approximately one percent when heat loss was matched to heat production over a full 24-hour metabolic cycle. The new suit was coupled with a previously developed metabolic rate monitor in a series of human experiments. It was shown that during 30-35continuous hours of monitoring body heat content is not constant,even at rest,and there is constant swing of heat storage of some magnitude;storage is generally ten percent of metabolic rate. Secondly,it was found that there are sinusoidal rhythms in heat production and heat loss,which are matched but out of phase,and the phase shift can explain the established circadian rhythm in rectal temperature. These data are of considerable interest to USAF laboratories studying physiological adjustments following flights over several time zones,changes in biological rhythms during prolonged flights,and in designing new protective equipment. (Author)