Design and Evaluation of a Personal Dry-Ice Cooling Jacket

Abstract

A personal dry-ice cooling jacket for workers in industrial heat stress environments was developed following three stages of prototype design and evaluation. Model-B2 was evaluated in two laboratory heat stress environments (dry-bulb temperatures of 35 and 45 °C) on two male subjects pedalling 60 minutes. Garment variables were dry-ice surface area and pocket insulation. Mean heart rate throughout the 60 minute exposure was 14 beats/min less with the jacket in the 45 °C environment and 18 beats/min less in the 35 °C environment. Mean rate of sweat loss was 0.06 kg/hr·m2 less with the jacket at 45 °C and 0.21 less at 35 °C. Mean rectal temperature was 0.61 °C less with the jacket at 45 °C and 0.49 °C less at 35 °C. Both the head and arm temperatures were significantly cooler while wearing the jacket. Oxygen uptake was 24% higher with the jacket, suggesting that heat production by non-shivering thermogenesis may occur when the jacket is worn. Dry-ice surface area affected skin and rectal temperatures.