HEAT STRAIN MODELS APPLICABLE FOR PROTECTIVE CLOTHING SYSTEMS - COMPARISON OF CORE TEMPERATURE RESPONSE

Core temperature (T-c) output comparisons were analyzed from thermal m odels applicable to persons wearing protective clothing. The two model s evaluated were the United States (US) Army Research Institute of Env ironmental Medicine (USARIEM) heat strain experimental model and the U nited Kingdom (UK) Loughborough (LUT25) model. Data were derived from collaborative heat-acclimation studies conducted by three organization s and included an intermittent-work protocol(Canada) and a continuous- exercise/heat stress protocol (UK and US). Volunteers from the US and the UK were exposed to a standard exercise/heat stress protocol (ambie nt temperature 35 degrees C/50% relative humidity, wind speed 1 m/s, l evel treadmill speed 1.34 m/s). Canadian Forces volunteers did an inte rmittent-work protocol (15 min moderate work/15 min rest at ambient te mperature of 40 degrees C/30% relative humidity, wind speed approximat e to 0.4 m/s). Each model reliably predicted T-c responses (within the margin of error determined by 1 root mean square deviation) during wo rk in the heat with protective clothing. Models that are analytically similar to the classic Stolwijk-Hardy model serve as robust operationa l tools for prediction of physiological heat strain when modified to i ncorporate clothing heat-exchange factors.