Cold Chills when temp over 100

[OakLeaf]

They're white, so they keep the sun off, and turn solar radiation into heat less than skin tone does, even fairer skin. They're some super duper wicking fabric, which is why someone mentioned they have to be skin tight, so they enhance evaporative cooling (either from sweat or in drier climates, from water you pour on them). Even at worst, in hot and humid weather, they're no hotter than bare arms (trust me, I've tried both ways when it's been 90° and humid), so at least they prevent sunburn, which lotions definitely keep you from sweating and for that reason alone aren't very safe when it's hot.

I'm not sure how much of a cooling effect the sleeves add at cycling speed. With the air flow you get at even moderate speed, it has to be pretty dang humid before bare skin drips with sweat. On the bike, I mainly use them just to keep the sun off. I really notice the cooling effect running at lower temperatures. When it's in the 70s it's pretty hot to be running with bare skin, but the sleeves make it really comfortable.