The WBGT combines the effect of the four main thermal components affecting heat stress: air temperature, humidity, air velocity, and radiant heat (included in outdoor) as measured by the dry bulb (Tdb), natural wet bulb (Tnwb), and globe temperatures (Tg). For outdoor environments, the meter uses all sensor data inputs in the following equation that weighs the wet bulb 70%, globe 20%, and dry bulb 10% of the weighted average: (WB)
| Variable | Unit |
|---|---|
| WBGT | Temperature F |
| tnwb | natural wet bulb temperature F |
| tg | globe temperature F |
| tdb | dry bulb temperature F |