Beat the Heat: Feel the Breeze for Cool Comfort

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Fletcher
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Why is it when I'm outside in the 90 degree weather the air feels incredibly hot, but when I get in my car and roll the window down and drive along the air blowing against me feels cold? The only difference is the air is moving across my skin, right?
 
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When you are sitting still in 90 deg weather, you have a micro-climate next to your skin that is becoming saturated with perspiration and the evaporative cooling is hard to feel. When you drive down the highway, the fast-moving air strips away that micro-climate and more evaporative cooling occurs, so you feel cooler.
 
This used to be much more obvious when you were allowed to pour organic solvents on your hands in high school!
 
mgb_phys said:
This used to be much more obvious when you were allowed to pour organic solvents on your hands in high school!

that's a completely different effect
 
It's still cooling by evaporation, but blowing on acetone is a much quicker example of the cooling effects than air.