ColdGear Infrared lining uses a soft, thermoconductive inner coating to absorb and retain body heat Material wicks sweat and dries really fast 4-way stretch material moves better in every direction 3-button front placket Odor control technology minimizes odor Loose: Fuller cut for complete comfort ColdGear Infrared technology holds in body heat, without adding weight or bulk. It's a special, soft print on the inside and it keeps you warmer, longer, so you can work out in the bitter cold.