For example if you are sitting in a car with the windows down and the air outside is hot. Yet when you start moving the air feels much colder.
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Vapor pressure https://en.wikipedia.org/wiki/Vapor_pressure
Evaporation of sweat (primarily water) cools your body because the molecules making the transition from liquid to gas remove heat. When the body of air reach the vapor pressure of the liquid being evaporated the net evaporation and thus the cooling stops because as much water gas is becoming liquid as liquid is becoming gas. When a breeze comes along that vapor pressure is never realized so the cooling continues as long as there is a breeze. If you have ever been to Arizona where the air is very dry you will notice that when you get out of a pool you will feel cold even on a warm day because the air around you will never reach the vapor pressure of water since it was so dry to begin with. Very different from a humid day in the midwest where the air might already be at the vapor pressure of water.
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