Table 3. Comparison of heat stress indices between indoor and outdoor environment .
| Variables | Indoor | Outdoor | P value |
| Wet-bulb globe temperature (WBGT) (°C) | 0.001 | ||
| Mean (SD) | 31.96 (2.8) | 26.42 (1.31) | |
| Range | 11.00 | 8.48 | |
| Predicted heat strain (PHS) (g/h) | 0.001 | ||
| Mean (SD) | 976.73 (191.92) | 603.94 (109.79) | |
| Range | 680 | 670 | |
| Heat stress index (HSI) (%) | 0.001 | ||
| Mean (SD) | 140.53 (27.98) | 57.95 (10.94) | |
| Range | 102.89 | 60.08 | |
| Discomfort index (DI) (°C) | 0.001 | ||
| Mean (SD) | 34.69 (2.98) | 28.80 (1.68) | |
| Range | 11.69 | 10.30 | |
| Corrected effective temperature (CET) (°C) | 0.001 | ||
| Mean (SD) | 29.21 (0.33) | 28.49 (0.82) | |
| Range | 1.26 | 3.43 | |
| Effective temperature (ET) (°C) | 0.001 | ||
| Mean (SD) | 28.79 (0.98) | 26.43 (1.26) | |
| Range | 3.56 | 5.75 |