Meter displays relative humidity, temperature, heat index, and wet bulb globe temperature (WBGT). A WBGT reading is produced through the use of a unique black globe on top of the meter. The globe monitors the effects of direct solar radiation on an exposed surface. An in/out function displays the WGBT value with or without direct sun exposure. The heat stress index measures how hot it really feels when humidity is combined with temperature, air movement and WBGT. Features include a choice of readings in °F and °C, data hold, measurement mode, auto off with override, and RS-232 interface.