Air/CO2 cooling garment: Description and benefits of use for subjects exposed to a hot and humid climate during physical activities

Abstract

The severity of the hot and humid conditions to which miners are exposed increases as the depth of the work site increases. This can cause heat stress that can greatly affect the health and safety of workers. To resolve this, a cooling garment has been developed that uses an atmospheric discharge of liquid CO2 to create a cool microclimate with an average temperature of 12.5 (±0.4) °C beneath the garment. To evaluate the garment’s cooling efficiency, 19 male subjects participated in an experimental procedure. The two modes, cooling on and off, were compared. Significant physiological differences were found between the two modes after minute 27 (p < 0.05) until the end of the recovery phase for the heart rate (maximum difference of 10 beats per minute) and the internal body temperature (maximum difference of 0.33 °C). It was found that the modes also affected the subjects’ perceptions. The ON-mode was associated with better well-being and thermal comfort, and reduced humidity sensation. Perceptions of exertion were lower in the ON-mode condition from minute 2. The findings provide strong evidence of the ability of this cooling garment to reduce heat stress in hot and humid conditions similar to those encountered in deep mines. Keywords: Cooling garment, Deep mining, Hot and humid, Liquid CO2 expansion, Physiological measurements, Perceptual responses