Comparison of physical, biophysical and physiological methods of evaluating the thermal stress associated with wearing protective clothing.

Abstract

Results from hooted, flat plate measurements of materials used in the standard U.S. combat uniform and in three different CVV protective clothing ensembles (two U.S. and one U.K. ) are compared to the insulation and evaporative heat transfer properties of the uniforms made from these materials as measured On a static heated copper manikin. The relative rank of these 4 uniforms, with and without M17 gas mask, with respect to heat stress imposed on soldiers working in a hot environment, and the body heat storage during a 3-5 mph treadmill march for 110 min (50 min march, 10 min rest, etc. ) in a climatic chamber at 35°c, 50% RH with 3 mph wind were predicted from these static measurements. Physiological chamber trials wore then conducted under the specified conditions with 8 volunteer subjects to evaluate the accuracy of the rank ordering and of the heat storage predictions. The results confirm the relative ranking with respect to heat stress of these uniform systems from the static measures. However, the a...