The key to staying warm during winter camping and other winter activities is to stay dry. This is done by dressing in layers which are easily vented. While snow shoeing, hiking, or downhill or cross country skiing, an individual generates an enormous amount of body heat. Unless the person is careful, the body will overheat, and the person will begin to perspire. When the person stops to rest, the perspiration will begin to chill the body. It is therefore imperative that the active person dress in layers.
When the body begins to heat up, the outer jacket should be vented, which is to say, unzipped. Modern winter jackets often have built in vents under the arms as well. If heat continues to build, the outer jacket should be removed. If this does not cool the body enough to end perspiration, another layer should be vented, and perhaps shed. The goal is to match the amount of clothing to the person’s level of activity. Retain enough body heat to keep warm, but not sweaty. When you slow down or rest, add clothing back or zip up again. If it is snowing, sleeting, or raining, as it often is in Vancouver, be sure the outermost layer is waterproof.
If you find that you have not controlled your perspiration sufficiently, it is important to change out of the sweat-soaked garments as soon as possible. Once the chills set in, they are difficult to overcome. Cotton will keep you warm only if it is kept perfectly dry, and keeping it perfectly dry is nearly impossible so do not wear cotton garments for winter camping. Experienced outdoor people know that cotton kills, so wear woolen or synthetic garments instead.
When the day’s exertion ends, it is time to start adding layers again. When it is finally time to go to bed, the winter camper should climb into a warm sleeping bag and zip up. If you start sweating in your bag, you need to vent so that outside air can cool your body.
Sleeping bags are rated by temperature. Make sure the temperature rating matches the expected weather conditions, and a bit more in case the temperature drops lower than expected. Also, remember that weather forecasts are for urban areas, not higher in the mountains where you may be camping and exercising.
