"Regulating your temperature is a near impossibility at high altitudes, where temperatures can swing by double digits within seconds," says one Rockies tester. "But these socks kept my feet comfortable from treeline to summit and back on a late-season climb of Longs Peak." Credit the merino wool's plush interior, ample cushioning, and above-the-calf cut.
"My toes are always cold, but not so with the warmth boost I got from the extra-long coverage," says another editor. With nylon reinforcements in the heel and toe, plus a Lycra knit throughout the sock's body, durability is bomber and fit is adequately snug. $24; darntough.com