Practical pre-cooling methods for occupational heat exposure

This study aimed to identify a pre-cooling method to reduce the physiological and perceptual strain, and the inflammatory response, experienced by individuals who wear personal protective equipment. Eleven males (age 20 ± 2 years, weight 75.8 ± 9.3 kg, height 177.1 ± 5.0 cm) completed 15min pre-cooling (phase change vest [PCV], forearm cooling [ARM], ice slurry consumption [ICE], or a no cooling control [CON]) and 45min intermittent walk (4 km h-1, 1% gradient) in 49.5 ± 0.6 °C and 15.4 ± 1.0% RH, whilst wearing firefighter ensemble. ICE reduced rectal temperature (Tre) before heat exposure compared to CON (ΔTre: 0.24 ± 0.09 °C, p < 0.001, d=0.38) and during exercise compared to CON, ARM, and PCV (p=0.026, ηp 2=0.145). Thermal sensation was reduced in ICE and ARM vs. CON (p=0.018, ηp 2=0.150). Interleukin-6 was not affected by precooling (p=0.648, ηp 2=0.032). It is recommended that those wearing protective equipment consume 500 ml of ice slurry 15min prior to work to reduce physiological and perceptual strain.