Table 2. The levels of physiological equivalent temperature(PET) and universal thermal climate index(UTCI) (Jo, 2017)
Thermal perception | PET (°C) | UTCI (°C) | Grade of physiological stress |
Very cold | <4 | <—40 | Extreme cold stress |
—27∼—40 | Very strong cold stress |
Cold | 4∼8 | —13∼—27 | Strong cold stress |
Cool | 8∼13 | 0∼—13 | Moderate cold stress |
Slightly cool | 13∼18 | 9∼0 | Slight cold stress |
Neutral | 18∼23 | 9∼26 | No thermal stress |
Slightly warm | 23∼29 | | Slight heat stress |
Warm | 29∼35 | 26∼32 | Moderate heat stress |
Hot | 35∼41 | 32∼38 | Strong heat stress |
Very hot | >41 | 38∼46 | Very strong heat stress |
>46 | Extreme heat stress |