Body Cooling in Wet and Dry Clothing

¹ From the Aero Medical Laboratory, Wright Air Development Center, Wright-Patterson Air Force Base, Ohio

Skin, rectal and extremity temperatures of clothed subjects were measured. The subjects were immersed in extremely cold water (0°C) for very brief periods of time, then exposed, while occupying a life raft, to ambient air temperatures ranging from +4.4° to –28.9°C. Amount and partitioning of the water absorbed by the clothing and effects of water immersion upon metabolic level were determined. Total water absorbed during an immersion period of from 15 seconds to 2 minutes amounted to 9–10 pounds. Mean metabolic increase due to wearing wet clothing was 54.7%. Total body heat storage loss was measured in both dry and wet clothing exposures and mean body cooling curves plotted. Mean body cooling rates for subjects wearing wet clothing were significantly greater (from 49.3% at –40°C to 22.2% at +10°C) than rates observed with dry-clothed subjects. On the basis of total body heat storage loss, a series of predictive curves for human tolerance is presented for both dry- and wet-clothed subjects exposed in a life raft to various low air temperatures.