Table 1.

Thermal indices and their input variables.

Thermal Indices	Full Name of the Indices	Air Temperature	Air Humidity	Wind Speed	Radiation
UTCI	universal thermal climate index	Ta	e	Va	R
indoor UTCI	UTCI for indoor environment	Ta	e
outdoor shaded UTCI	UTCI for outdoor shaded space	Ta	e	Va
MRT	mean radiant temperature				R
ESI	environment stress index	Ta	RH		SR
HI	heat index	Ta	RH
Humidex	humidity index	Ta	e
WBGT	wet-bulb globe temperature	Ta	e
WBT	wet bulb temperature	Ta	RH
WCT	wind chill temperature	Ta		Va
AT	apparent temperature	Ta	e	Va
NET	net effective temperature	Ta	RH	Va

Note: T_a, e, and RH represent the air temperature, water vapour pressure, and relative humidity, respectively. V_a stands for the 10-metre wind speed, with the exception of the NET (Eq. 12), which requires an input of wind speed at 1.2 m above the ground. R stands for the radiation variables, including direct, diffuse, and reflected solar radiation, as well as upward and downward thermal radiation, while SR represents the solar radiation, which includes both the direct and diffuse solar radiation reaching the horizontal surface of the Earth. The indoor UTCI, outdoor shaded UTCI, and UTCI, which take 2, 3, and 4 parameters, respectively, are applicable to indoor, outdoor shaded, and outdoor unshaded environments. All indices are with a unit expressed in °C.