Air-conditioning in cars and houses keeps us comfy in the summertime, but once we step into the great outdoors, it's much harder to beat the heat. Columbia, which gave us electric jackets and boots to keep us toasty warm in winter, aims to keep us cool during the dog days of summer with its new line of Omni-Freeze Ice clothing. The material that makes the magic happen is made of flat fibers that bring 35 percent more surface area in contact with your skin than traditional round yarns -- and the more cloth touching
