The Relationship Between Wet Bulb Globe Temperature and Physiological Strain Index in Muslim Women in Hot-Dry Condition in the Climatic Chamber

Abstract

Background: The heat strain is one of the consequences of heat exposure in the work place. Different factors such as dry, wet, and radiant temperature, the intensity of physical activity, the kind of clothing, and the percentage of body covering affect the heat strain. Objectives: The purpose of this study was to determine the association between the wet bulb globe temperature and the physiological strain index in Muslim women in hot-dry condition in the climate chamber. Patients and Methods: This experimental study was performed on 30 healthy Muslim women with wearing Islamic clothing in two hot-dry climatic conditions with wet bulb globe temperature index (WBGT) of 32℃ ± 0.1℃ and 30℃ ± 0.1℃ respectively in sitting and light workload. The WBGT, oral temperature, and heart rate (HR) were measured. The data were analyzed based on descriptive statistics and Pearson correlation tests. Results: The results showed that the average HR at resting, sitting (32℃ ± 0.1℃), and light workload (30℃ ± 0.1℃) were 78.52 ± 12.10, 69.74 ± 11.98, and 110.78 ± 17.91 beat/min, respectively. The average of ear canal temperature was estimated at 36.70℃ ± 0.36℃ for sitting workload and at 36.71℃ ± 0.27℃ light workload. Conclusions: The findings of this study illustrated that the average HR and the core temperature measured in both sitting and light workload in hot-dry climatic condition were less than the threshold limit values established by the national institute for occupational safety and health(NIOSH) and American conference of governmental industrial hygienists (ACGIH). Comparing different HR and core temperatures during rest and activity showed a significant increase in the incidence of heat strain.