Best for Extreme Cold
"Mountain guides swear by these," reports our tester, herself a Tetons guide who packed these superlight mittens on trips to Antarctica, Alaska, and Argentina last winter, encountering temps that dipped to
-40°F. It's a two-piece system; each layer can be worn alone. The outer layer is a waterproof, gauntlet-style Gore-Tex shell with a leather palm for grip, PrimaLoft One insulation on the back of the hand, and fleece in the palm.
The inner layer uses the same insulation combination (but more of it), and even when combined the fit is roomy enough to allow wiggle room (important to keep circulation going). "And I love the long cuffs," says our tester. "They kept snow from blowing in when I was pounding pickets near the South Pole." $199; 11 oz.; orgear.com