Dry bulb is the temperature independent of humidity. Wet bulb is has a wet cloth on the thermometer bulb. This simulates how much sweat cools you in the current humidity and wind.
Measuring humidity instead and cross-referencing to get heat index is more common these days, but IMO it’s worse. 120 in the desert vs 120 heat index due to humidity is the difference between someone using a hair dryer on your face and getting cooked in a steam room, and it doesn’t consider wind and cloud cover.
Dry bulb is the temperature independent of humidity. Wet bulb is has a wet cloth on the thermometer bulb. This simulates how much sweat cools you in the current humidity and wind.
Measuring humidity instead and cross-referencing to get heat index is more common these days, but IMO it’s worse. 120 in the desert vs 120 heat index due to humidity is the difference between someone using a hair dryer on your face and getting cooked in a steam room, and it doesn’t consider wind and cloud cover.