the effect of cooling vest on heat strain indexes and reaction time while wearing chemical-microbial-radioactive protective clothing in hot and dry laboratory conditions

background heat is a harmful factor in workplaces that causes physiologic and cognitive changes in workers. objectives the purpose of this study was to investigate the effect of cooling vest on heat strain and reaction time while wearing chemical-biological-nuclear protective clothes. methods twelve male students with mean age of 25 ± 2 and body mass index (bmi) of 23 ± 1.5 were recruited in the experiment. each student ran on a treadmill with a speed of 2.4 km/hour in the climate chamber at 35°c and 30% relative humidity. physiological strain index score, oral temperature, heart rate, reaction time and number of errors were measured at the end of the two levels and analyzed by the spss software. results wilcoxon test showed that the differences of physiological strain index score (p = 0.02), oral temperature (p = 0.02), reaction time (p = 0.02), heart rate (p = 0.02) and errors (p = 0.03) with and without the cooling vest were significant. the mean physiological strain index score without cooling vest was 4.038 ± 0.882 and with the cooling vest was 1.42 ± 0.435. the mean reaction time without and with the cooling vest was 0.769 ± 0.0972 and 0.539 ± 0.977, respectively. conclusions the results of the study showed that the cooling vest reduces the physiological strain, reaction time and errors rate of workers.