Thermal effects of rayon and polyester hijabs in warm-humid and hot-dry environments

Hijabs are predominantly worn in hot environments, but very rare studies on the thermo-physiological effects of wearing hijabs are found. We investigated the effects of wearing rayon and polyester hijabs on wearers’ physiological and subjective responses in warm-humid and hot-dry environments. Eight females (25.0 ± 2.3 y in age, 157.7 ± 4.1 cm in height, and 50.8 ± 7.5 kg in weight) participated in three conditions (No hijab, rayon hijab, and polyester hijab condition) during exercise in two thermal environments: a warm-humid (30 °C and 70%RH) and a hot-dry environment (36 °C and 30%RH), which generated an identical wet-bulb globe temperature at 27 °C. The results showed that no differences in rectal temperature were found among the three clothing conditions or the two environments, whereas auditory canal temperature was higher in the hot-dry than in the warm-humid environment (P < 0.05) with no differences between the polyester and rayon hijab conditions. Mean skin temperature and neck temperature were higher for the polyester condition than for the rayon condition in the warm-humid environment (P < 0.05). Sweat rate was greater for the polyester hijab condition than for the no hijab condition in the warm-humid environment (P = 0.049). Heart rate was greater for the polyester hijab condition than for the other two conditions in the warm-humid environment (P < 0.05). Subjects felt more thermally uncomfortable when wearing the polyester hijab than the rayon hijab in the warm-humid environment. Greater thermal burden of the polyester hijab when compared to the rayon hijab was marked in the warm-humid environment, not in the hot-dry environment.