In the WBGT metrics, which term represents natural wet-bulb temperature?

• A. T_g
• B. T_nwb
• C. T_d
• D. T_w

Answer: (B)

In WBGT calculations, the component that captures evaporative cooling under natural air movement is what reflects how humidity and ambient wind affect sweat evaporation in real outdoor conditions. This natural wet-bulb temperature is the value used to represent that evaporative process, and it is the symbol that corresponds to the outdoor WBGT component. The other terms correspond to different physical quantities: dry-bulb temperature is the ambient air temperature, globe temperature measures radiant heat from sun and surroundings, and an aspirated (forced-air) wet-bulb measurement represents a different, not-natural cooling condition. So the natural wet-bulb temperature effectively represents the evaporative cooling aspect within WBGT, making it the best match.