In the outdoor WBGT calculation, which coefficient is applied to the Dry Bulb temperature?

• A. 0.1
• B. 0.2
• C. 0.7
• D. 0.3

Answer: (A)

Outdoor WBGT uses a weighted combination of three measurements: natural wet-bulb temperature, globe temperature, and dry-bulb air temperature. The standard weights are 0.7 for the wet-bulb, 0.2 for the globe, and 0.1 for the dry-bulb. This reflects that humidity and radiant heat have a larger impact on heat stress outdoors, while the plain air temperature contributes the least. So the coefficient applied to the Dry Bulb temperature is 0.1. (Note: the 0.3 weight appears in some indoor WBGT formulations, not the outdoor, solar-loaded one.)