Aims: The aim of this study was to evaluate the relationship between environmental and physiological heat stress indices based on heart rate (HR), oral temperature for the estimation of heat strain, in veiled women in hot-dry condition in the climate chamber. Materials and Methods: The experimental study was carried out on 36 healthy Muslim women in hot-dry climatic conditions (wet bulb globe temperature (WBGT) = 22-32°C) in low workload for 2 h. The HR, oral temperature and WBGT index were measured. The obtained data were analyzed using descriptive statistics and Pearson correlation tests. Results: The results of the Pearson test indicated that physiological strain index was a high correlation (r = 0.975) with WBGT index (P < 0.05). Also, there was a good correlation among WBGT and HR (r = 0.779) and oral temperature (r = 0.981). Conclusion: The findings of this study illustrated that there is a good correlation between environmental and physiological heat stress indices in veiled women with Islamic clothing at the low workload over the action limit (WBGT = 31°C). So that it can be concluded that the WBGT 22-32°C is a good indicator of the heat strain in veiled women with Islamic clothing.