Castelli Chill Arm Sleeves

In the heat of summer, we'd like to think that wearing "cooling" clothing actually does just that. And while you'll feel cooler in the Castelli Chill Arm Sleeves, it's actually your own body doing the cooling, with a little extra help. The Prosecco Ice Material with Xylitol doesn't magically cool your skin. What it does do is provide evaporation of water, which, in turn, produces the tangible cooling effect. The Castelli branded design on the sleeves actually disappears when you start to heat up, and this alerts you to dump some water on your sleeves--their construction is meant to absorb and hold water, prolonging the effects of cooling evaporation. The UPF is 50 to provide sun protection.