>>510586185It's a combination measurement of air temperature and humidity. The wet bulb temperature is what the air temperature would be if you cooled it down until the air reaches saturation, or 100% relative humidity. This is like how you cool off by sweating and the sweat evaporates. If the wet bulb temperature is high, it's not only hot, but unbearably humid and sticky.
If the wet bulb temperature passes 95ยฐF, that's when it gets dangerous. It's so hot, and the air is so thick with humidity, sweating is ineffective at cooling you off because the air is so choked with moisture. That's when you suffer heat exhaustion and heatstroke.
>t. atmospheric science degree