Evaluation of Three Cold Weather Ensembles with a Heated Base Layer at -20 Degrees C Using a Thermal Manikin with Dynamic Heat Flux Sensors

The goal of this project was to determine the efficacy and performance of a heated clothing system when it is used with three Air Warrior ensembles at different environmental conditions. The baseline thermal properties of the heated base-layer (heat off), and three Air Warrior ensembles (each worn over the unpowered base layer) were measured (see Xu et. al, USARIEM tech report T23-004). In the present series of tests, three Air Warrior ensembles with a heated base-layer (Human Systems Integration (HSI), East Walpole, MA) were measured to determine the heating power provided by the HSI system. The three Air Warrior ensembles were light, intermediate, and cold weather ensembles. They were tested on an ANDI thermal manikin (Thermetrics, Seattle, WA) in a -20 degrees C environment while the active heating system was turned on at power levels of low, medium, and high. The heat gains, i.e., the heat from the HSI heated layer to the manikin, ranged from approximately 25 W to 48 W. This heat was distributed to four body regions: torso, thighs, hands, and feet.