Cold water survival suits for aircrew.

Laboratory and sea trials were used to compare the effectiveness of three aircrew exposure garments--the British Mark 10, the United States CWU 21/P, and the Canadian U.VIC. Thermofloat jacket. The first two are waterproof coveralls, whereas the third is a neoprene-lined jacket designed on the basis of the "wet suit" concept. Rectal and skin temperatures, electrocardiograms and other variables were measured while subjects, wearing the suits, were immersed in water at temperatures of 70 degrees C and 10.5 degrees C. The three garments were found to be similar in the degree of thermal protection provided, but the Thermofloat jacket appeared superior in other ways and has the greater potential for development. A previously unreported observation was a marked reduction in core cooling rate after the expected linear fall in core temperature. This has possible implications in the conduct of research in this field.