RT - Journal Article T1 - Investigating the Association between Heat Stress and its Psychological Response to Determine the Optimal Index of Heat Strain JF - umsha-johe YR - 2014 JO - umsha-johe VO - 1 IS - 1 UR - http://johe.umsha.ac.ir/article-1-22-en.html SP - 8 EP - 15 K1 - Heat stress K1 - Heat strain K1 - Hot workplaces K1 - Tympanic temperature AB - Background & Objectives : Exposure to high temperatures is common among workers in warm environments leading to some undesirable effects . The aim of this study was to examine physiological responses to heat stress to determine the optimal index for direct measurement of physiological strain in workers of hot environments . Methods: In this study, 40 workers of melting and casting process were evaluated . Thermal stress was evaluated based on the WBGT index and physiological strain by measuring oral and tympanic temperature , urine temperature , heart rate, and recovery heart rate. Data was analyzed using SPSS v.16 software . Results : Heat stress exceeded the national and international recommended limits based on the WBGT index in 80% of cases of workstations . The correlations between heat strains including tympanic temperature, oral temperature, urine temperature, heart rate and heart rate recovery to heat stress index were significant, while tympanic temperature had a stronger association according to simple linear regression (P<0.01, R2=0.78) . Conclusion: Tympanic temperature had a stronger correlation with the WBGT index among the investigated indices . Accordingly , tympanic temperature could be a useful indicator compared to other parameters for measuring physiological strain in warm workplaces due to the ease of measurement, noninvasive nature , acceptance by workers , and fast and non- interference in the measurement process . LA eng UL http://johe.umsha.ac.ir/article-1-22-en.html M3 ER -