Personal Cooling With Dry Ice

Abstract

Eighteen experiments with a male student subject evaluated some of the characteristics of dry ice cooling. Skin and rectal temperatures, heart rate, blood pressure, ice sublimation and sweat evaporation rate, and environmental conditions were measured. Heat balances were calculated. The mechanism of cooling is conduction from the dry ice plus sweat evaporation. The amount of cooling depends on the initial amount of dry ice, its shape and the insulation. Humidity and air velocity did not substantially affect the cooling from the dry ice. For the clothing designs in the last few experiments, the dry ice vest provided about 79 kcal/hr of cooling benefit to the man.