Effect of Palm Cooling with Negative Pressure on Heat Balance During Exercise in a Hot, Dry Environment

摘要

Military personnel often must work in hot environments, increasing the risk of hyperthermia. Our purpose was to evaluate a new rapid thermal exchange device (RTX) in slowing the development of hyperthermia and associated symptoms to 3 other conditions hand immersed in water bath (WB), water- perfused vest (VEST), and a no- cooling condition (NC) in subjects exercising in a hot environment (42C, 30% rh) wearing summer fatigues, a backpack and body armor. Ten subjects (age 25+/-3 yrs; weight 74+/-6 kg) performed 4 heat stress tests in a counter-balanced order (NC/RTX/WB/ VEST) The protocol consisted of two bouts of treadmill walking (at 50% VO2max), separated by a 41-min cooling and rehydration period. The time to reach a pre-determined rectal temperature (Tr) in the 1st and 2nd bouts were not different among RTX (mean +/- SD; 52+/- 14 and 42+/-l2 min respectively), NC (49+/-13 and 4l+/-14 min respectively), and WB (54+/-14 and 55+/-20 min respectively), but was longer for the VEST (85+/-30 and 65+/-12 min respectively) in both bouts.