UA CoolSwitch uses an exclusive coating on the inside that pulls heat away from your skin, so you actually feel cooler. Mesh HeatGearfabric, with all the benefits of UA Compression, delivers total ventilation. 4-way stretch construction moves better in every direction. Material wicks sweat & dries really fast . Anti-odor technology prevents the growth of odor-causing microbes. Smooth, chafe-free flatlock seam construction.