A baselayer is the most important piece of clothing you'll wear during winter, as it's the layer that directly touches your skin. Yes, it should to be soft and comfortable, but, most importantly, it needs to wick moisture and maintain warmth. The X-Bionic Energy Accumulator pants manage temperature and keep sweating to a minimum using five distinct zones that correspond to different parts of the body. Thicker panels on the quads and hips keep those sections warmer, while thinner panels on the inner thighs and behind the knee allow heat to escape.
The knees are lined with silver to reflect heat inward even as the fabric is stretched when flexing. In particularly sweaty zones like above the tailbone, the fabric panel is extra absorbent to clear moisture. The zones work: For such a thick, warm base layer, it kept us remarkably dry when skiing hard even on days when the temps on the slopes climbed into the low thirties. The Swiss-made pants provide a degree of compression, too — a function that's been receiving a lot of attention lately. And whether or not you believe the hype about how these layers help increase muscle endurance, believe us: We were able to ski longer and harder in the pants. Perhaps it's the compression. Or perhaps it's the comfort. Either way, they made our time on the mountain all the better. [$225; x-bionic.com]
Days Tested: 18
Areas Used: Jackson Hole, Wyoming; Snowbird, Utah; Davos, Switzerland
Activities: Downhill skiing
Conditions Encountered: Temps ranging from 5 to 40 degrees
Nitpick: They are triple the price of many baselayers.