Iranian Journal of Health, Safety & Environment, Vol.1, No.4, pp.172-176 172 Physiological and perceptual heat strain responses in Iranian Veiled women under laboratory thermal Conditions Peymaneh Habibi 1,2 , Habibollah Dehghan *1 , Shiva Rezaei 1 , Kobra Maghsoudi 1 1) Department of occupational health engineering, school of health, Isfahan university of medical sciences, Isfahan, Iran. 2) Department of occupational health engineering, research center, school of health, Isfahan university of medical sciences, Isfahan, Iran. *Author for Correspondence: ha_dehghan@hlth.mui.ac.ir Received:19 May. 2014, Revised: 26 Jul. 214, Accepted: 10 Aug. 2014 ABSTRACT Heat stress risk assessment, as a harmful agent at workplace, is essential for controlling heat strain. The purpose of this study was relation between physiological and perceptual heat strain responses in Iranian veiled women under laboratory thermal conditions. This experimental study was carried out on 36 healthy females (age 22.3 ± 2.0 yr., height 162.76±5. 57cm, weight 55.82 ± 9.27kg) in sitting state under thermal conditions (27 - 38° C) in the hot-dry climatic condition for 120 min. In order to calculate the physiological strain index (PSI), oral temperature and heart rate were measured every 5 min. Physiological factors, and Heat Strain Score Index (HSSI) questionnaires are simultaneous measurements taken at any 5 min during the exposure and physiological factors, and Heat Strain Score Index (HSSI) questionnaires are the initial measurements. The data were analyzed using correlation and line regression by test spss16. The results showed that the average heart rate and oral temperature at resting and sitting were between 83.06 ±9.41bpm, 87.91 ±7.87 bpm and 36.7° C, 37. 1°C respectively. Also, the results have revealed a direct and significant and direct correlation among HSSI with WBGT (R 2 = 0.97, P≤ 0.001), PSI (R 2 = 0.96, P≤ 0.001), oral temperature (R 2 = 0.96, P≤ 0.001) and heart rate (R 2 = 0.62, P≤ 0.01) indices. The results have shown that simultaneously with the increase in valid indices of heat stress evaluation such as WBGT and PSI indices, the amount of HSSI index has also increased with high power. Therefore, it can be conclude that when there is no access to a reliable heat stress method such as WBGT or PSI indices, HSSI index, an objective and subjective heat strain method, can be used as a simple, fast and inexpensive method for evaluating the heat strain in women. Keywords: Heat Stress, Heat Strain Score Index, Physiological Strain Index, Wet Bulb Globe Temperature , Veiled Women. INTRODUCTION Heat stress indices are effective techniques that predicted severity heat stress in workers population [1].In some workplaces, employees are exposed to heat, which may deteriorate work efficiency, safety and productivity. Additionally, the risk of heat- induced illnesses such as heat cramps, heat stroke increases with additional heat stress [2, 3]. Heat stress evaluation is needed in order to heat stress measures control. These heat stress indices should be noticed based on parameters such as capability of applying a wide range of metabolic rate and environmental conditions, taking into account important factors related to heat stress (ambient temperature, clothing, etc.), measuring the amount of heat exposure without interfering the activity workers. Heat exposure limits should be reflected by physiologic and psychological responses reflecting increased hazard and safety in employees [3]. Due to the importance of healthy human workforce in productivity and the importance of heat as a harmful factor, it is necessary that heat exposure to be evaluated for having an effective heat stress control. Therefore heat strain indices have been developed. These indices are able to predicate effective techniques in estimating heat strain level in the workers population. Each of the heat stress indices has limitations for example wet bulb globe temperature index, (WBGT), that its used to evaluate the heat stress in worldwide [4], prolonged the time of globe temperature measuring [5] or physiological strain index (PSI) was developed to evaluate physiological strain which considers the load into the cardiovascular system and regulation of body