Baseball caps are nice, but they aren't the techiest gear out there. The Mountain Hardwear Women's Chiller Ball Cap, however, is smarter than your average trucker hat. The Chiller's stretchy, quick drying nylonelastane fabric blend is complemented by Cool. Q Zero sweat activated cooling panels on the forehead and sides that provide a cooling sensation during evaporation. UPF 25 sun protection is built in, and closed cell foam in the brim makes sure that the Chiller will float if it goes overboard.