Background:
Some environmental factors such as the ambient temperature, radiant temperature, humidity and air velocity as well as clothing and activity level are effective to induce heat strain on the workers.
Objectives:
The current study aimed to evaluate the effect of air velocity on Iranian veiled females at various exercise intensities and climatic conditions.
Methods:
The current experimental study was conducted on 51 healthy veiled females with Islamic clothing (n = 30) in two hot-dry climatic chambers (wet-bulb globe temperature (WBGT) = 32 ± 0.1°C and WBGT = 30 ± 0.1°C, 40% relative humidity (RH) without air velocity and (n = 21) with air velocity 0.31 m/s in sitting and light workload conditions, respectively, for 60 minutes. The WBGT, oral temperature and heart rate were measured simultaneously every five minutes during the heat exposure and resting state. Data were analyzed using correlation and line regression by SPSS ver. 16.
Results:
In both groups, oral temperature and heart rate increased during heat exposure. The increase of oral temperature and heart rate were larger in the group with air velocity (sitting position, 37.05 ± 0.20°C, 98.30 ± 7.79 bpm, light workload, 37.34 ± 0.24°C, 124.08 ± 6.09 bpm) compared those of the group without air velocity (sitting position, 36.70 ± 0.36°C, 69.74 ± 0.98 bpm, light workload, 36.71 ± 0.27°C, 110.78 ± 17.9 bpm). The difference in physiological strain index (PSI) between resting and low workload were higher in with air velocity group than those of the group without air velocity.
Conclusions:
The results showed that the heat stress increased by increasing air velocity and humidity in both groups. The air velocity with high humidity can be considered as a positive factor in the occurrence of heat strain. Therefore, the incidence of heat stress decreases with the increase of humidity and reduction of air velocity or with increase of air velocity and reduction of humidity in Iranian veiled females.
Keywords:Air Velocity, Physiological Strain Index, Climatic Chamber, Veiled Females