Updated and improved, the Wigwam Outlast Weather Shield hiking sock is more efficient than ever. Outlast and Wool make the perfect temperature regulator that keeps feet warm in cold weather and cool in hot weather. The all-around perfect sock for hitting the trail. Whether you're a summer hiker, or like to take in the beautiful fall foliage, the Wigwam Outlast Weather Shield Crew Sock is for you. Outlast is NASA-tested and approved. With Outlast you get the warmth you need, when you need it, without the bulk.