What are the components of a WBGT?

• A. Wet bulb temperature, Dry bulb temperature, Black globe temperature
• B. Wet bulb temperature, Relative humidity, Air pressure
• C. Dry bulb temperature, Wind speed, Radiant heat
• D. Black globe temperature, Humidity, Barometric pressure

Answer: (A)

WBGT is a heat-stress index that combines three measurements to capture air temperature, humidity/evaporative cooling, and radiant heat. The wet-bulb temperature represents how much evaporative cooling is possible and is influenced by humidity; the dry-bulb temperature is the actual air temperature; the black globe temperature measures radiant heat from the sun and surroundings. Together, these three components reflect the total environmental heat load an individual experiences, which is why they are the essential parts of WBGT. The other options mix in humidity, pressure, or wind in ways that aren’t the components used to form WBGT.