Evaluation of Iranian Cooling Vest (Spadana Ice Gel) and Phase Change Material Cooling Vest (Paraffin) on Physiological Strain Indices among the Workers in Hot-Wet Condition of Asaluyeh Region, Iran

To prevent heat stress in hot environments, it is essential to reduce the level heat stress among the workers. This study aimed to compare the effect of two kinds of cooling vests [Iranian cooling vest (Spadana ice gel) and phase change material cooling vest (paraffin)] on physiological strain indices (PSI) among the workers in hot-wet conditions of Asaluyeh region, Iran.
This cross-sectional and interventional study was conducted on 90 workers in Asaluyeh region in the summer in 2016 with the temperature of 47 °C and (RH) of 95%. Heart rate, oral temperature, perspiration, and the wet-bulb globe temperature (WBGT) index were measured for 120 minutes, in experiment groups, when using the 2 kinds of cooling vests, and in control group.
Findings: The mean WBGT was calculated as 37.65 °C for the three group. The mean heart rate was 91.76, 89.53, and 97.07 beats per minute in Iranian cooling vests group, phase change material cooling vest, and control groups, respectively; moreover, the mean oral temperature was 36.7, 36.63, and 36.78° C, and the mean physiological strain index was 3.18, 2.29, and 6.12, in the three groups, respectively. Physiological strain index was significantly difference between the experiment groups compared with the control group (P The study showed that Iranian Spadana cooling vest and phase change material cooling vest can reduce heat stress level for 90 minutes, in hot and humid conditions in the summer.