Thermal Stress Inside the XM-1 Tank Ddring Operations in an NBC Environment and Its Potential Alleviation by Auxiliary Cooling

摘要

Thermal stress inside an XM-1 tank parked in the desert was evaluated on heat-acclimated crewmen dressed in the standard Combat Vehicle Crewman (CVC) uniform plus various configurations of chemical protective clothing (i.e. Mission-Oriented Protective Postures MOPP i-IV). In addition, an auxiliary water-cooled vest (WVC) was tested for its potential in alleviating heat stress imposed on the active crewmen in a closed hatch, unventilated tank. Two tank crews (4 crewmen each) alternated exposures during the six days of testing. Days 1-3 (MOPP I, III, and IV) presented moderate heat stress to the crews, whereas on Days 4 and 6, the tank's environmental conditions with hatches closed and ventilator off were intolerable in MOPP IV. Exposure times on Day 4 and Day 6 were 80 and 124 min, respectively, with termination due to crew distress accompanied by high heart rates (HR) and/or convergence of mean weighted skin temperature (MWST) and deep body temperature (T sub re). The WCV on Day 5 appreciably reduced the heat stress by preventing convergence of MWST on T sub re; HR and T sub re responses were substantially lower with WCV as opposed to Days 4 and 6 when the vest was not worn. (Author)