Built for the coldest hiking and mountaineering conditions, the Merino Hike+ Mountaineer Mid Calf Sock is the warmest sock in icebreaker's collection. It layers on a highly dense, fully cushioned construction without sacrificing fit, thanks to an anatomically sculpted shape with support zones at the Achilles and instep. A seamless toe and reinforced heel keep friction and pressure points in check through a long day, while the merino wool blend regulates temperature and resists odor across repeated wear. What Our Gearhead® Experts Are Saying:"I wore these on a full day of trailbreaking in fresh snow and my feet stayed warm the entire time, even standing around at the trailhead afterward. The cushioning held up through hours in wet boots without ever feeling waterlogged or heavy."