Face shield Balaclavas are often overkill when you’re on the move. Alex Van Steen, a 21-year veteran of Rainier Mountaineering, Inc., advises a neck gaiter that you can pull up over your nose as needed; cut a dime-size hole over your mouth to keep your breath from fogging goggles.
Gloves On Rainier, Van Steen takes thin liners for dexterity, ski gloves for moderate warmth, and waterproof mittens for the worst weather. In extreme cold, never take the liners off.
Boots Whether or not you’re using insulated boots, make sure the fit allows wiggle in the forefoot when you’re wearing winter-weight socks. A tight fit can restrict circulation, causing dangerously cold toes.
Zipper pulls Extend zipper tabs–pants fly zipper included–by attaching three-inch lengths of cord. Now you can keep your thick gloves on while adjusting gear and layers.
Hot-water bottles Fill two, put them in socks (to avoid burning your skin), and nestle them at your feet and between your thighs, where the latter can warm the blood in your femoral artery.
Sleeping bag Too big and it’s chilly, but make sure it has extra space (about six inches at the foot) for clothes.
Hooded parka A mountain must, it’s way warmer than a hoodless parka and hat.
My Secret: Shelli Ogilvy
Your body needs extra calories in cold temps. When guiding in Antarctica and Alaska, Mountain Travel Sobek’s Ogilvy fuels up by putting peanut butter in ramen noodles and a hunk of butter in hot chocolate. She also adds heat to her diet with chili sauce and cayenne capsules: "Spicy foods just make me feel warmer," she says.