[Heat transfer, convection and altitudinal gradient].

Measurements of heat loss from fur covered aluminium cylinders were made under barometric pressures ranging from 760 to 368 torr (sea level up to 5.8 km, simulated altitudes). Heat transfer diminished at high altitudes and a relative greater diminution was observed when forced convection was applied. The virtual increase in thermal insulation at high altitudes may be useful to compensate the expected larger difference between body and ambient temperatures.