Pack the Right Foods
The key to a successful winter climbing adventure starts with good nutrition. Before setting out, make sure you pack foods that are both convenient to eat and work to keep your body warm and full of energy. Warm liquids like tea, broth, and soup are excellent to have in the clutch. In terms of food, those with high caloric and fat content (like dry salami, sausages, and beef jerky) burn slower and keep you cozy for longer. Also be aware that some foods -- like your go-to chocolate bar -- are prone to freezing in low temperatures.
In cold climates, you obviously want to stay warm, but overheating is sometimes just as detrimental. Sweating deprives the body of heat and leaves you with less defense against the cold. Make sure you pack a lineup of layers that aren’t too warm or constricting. Many climbers opt to “be bold and start cold,” in knowing that they’ll be working up a sweat. A good go-to formula is a thermal base layer, a fleece-type mid layer, and a shell on top.
Stock up on Warmers
Instant warmers have become an indispensable piece of equipment for any cold weather activity. Climbing is no exception. Stocking up on hand warmers, foot warmers, toe warmers, and even large adhesive warmers that keep your core warm are excellent ways to beat the freeze. If you’re just bouldering and looking to skimp on equipment, put some Heat Factory Hand Warmers in your chalk bag.
Keep Your Blood Flowing with Calisthenics
Aside from food, equipment, and clothing, one of the best things you can do to stay warm is to keep your blood flowing. Calisthenics -- really any kind of jumping jacks or active movement -- is a surefire way to keep your extremities not entirely miserable. Before hopping on the wall, make sure your hands and feet are as warm as possible. Shake them out, rub them together, and do what you need to do.
Follow the Sun
This may sound like a no-brainer, but if possible, try choosing routes that are either in the sun or ones that have been recently exposed to sunlight. Rock faces that have spent the morning basking in sun are going to carry some heat throughout the day.
Many people think that if they’re not sweating, they’re not losing any liquids. In cold weather environments, you actually become more dehydrated through respiration than through perspiration. Your lungs especially need to stay hydrated during your time on the rock. Make sure to stay hydrated at all times throughout your climb.
Pack the Right Gear
As a general rule of thumb, pack for the most intense situations. There’s nothing worse than showing up at the trailhead and realizing that you actually will need snowshoes, crampons, or an ice ax. Do your research and try to be reasonable, but always pack gear that takes everything into account.