[Photo: Menno Huber]
With the winter months upon us, staying warm on backcountry trips becomes a little more challenging; it requires careful attention to the gear list.
Staying warm while sleeping isn’t really all that difficult if that gear list includes a cold-weather-capable sleeping mat and a sleeping bag designed with enough insulation for the conditions and the human inside. Simply matching temperature ratings to ambient temperatures expected on the trip isn’t enough, however. The user’s metabolism, experience, conditioning and state of mind can all play big roles in achieving warmth. Sleeping bag and mat play very different roles and understanding them can make the difference in comfort.
It’s best to think of the sleeping bag as the tool for conserving heat that would otherwise be lost to the atmosphere - upward and outward heat loss. A sleeping mat is the part of a sleep system that limits heat loss into the ground - down and into the heat-hungry earth. In general, the colder the conditions the more insulation a person will need both top and bottom. We say in general because there remains the all-important human factor in the equation: is the user a warm or a cold sleeper? People usually know right away when asked if they sleep warm or cold. For cold sleepers, without exception, more insulation is better, while warm sleepers can often get away with less. To simplify this we usually recommend that cold sleepers use the warmest sleeping mat they can afford and use a sleeping bag with a colder-than-conditions rating. An example for the sleeping bag would be to use a bag rated to +23F even if temperatures will be around +32F (one bag rating warmer regardless of expected temperatures). Warm sleepers generally do pretty well using bags and mats rated to the expected temperatures.
We offer a wide range of sleeping bags, but for snow camping trips the new WinterLite is an outstanding choice. Available in 3 ratings (+21F, +3F and -44F) and built with a weatherproof shell (wind and moisture resistant), it’s a great choice for winter trips that can often involve melting ice and snow coming in contact with the bag surface. It’s also good to consider that a spilled soup or hot drink inside the tent can quickly become a small pond, making a sleeping bag vulnerable, hence the hydrophobic shell. Condensation on the inner tent surface from breath will often freeze on cold nights but melt rapidly when the sun hits the tent in the morning. Another reason for that sophisticated shell fabric.
In sleeping mats, for warm-ish sleepers, our SynMat UL Winter or SynMat HL Winter are both light and highly efficient insulators. But for those cold sleepers we strongly suggest pulling out all the stops with the warmest fast-and-light mats available anywhere: DownMat UL Winter and DownMat HL Winter. All of these mats are built with 20 denier fabric, so very light in weight. UL designates that the ultralight model in question is rectangular in shape and the HL means the mat is tapered at head and foot for ever more weight savings. Also, all of these mats are sold with the Schnozzel Pumpbag for rapid, lung-free inflation; no blowing vapor-laden air into the mat by mouth. Just a few bagfuls of captured air pushed into the mat by body weight!
Other things that will help keep a person extra-warm are, in no particular order:
* Wearing a set of dry sleeping clothing - don’t pour precious heat into the evaporation of sweat in wet layers
* Wear a balaclava to bed. It’s better than a hat because it covers the neck and can’t come off inadvertently
* Eat well - burning calories generates heat that can be trapped in the night
* Empty a full bladder when the time comes rather than heat that liquid (use a pee bottle instead of going outside!)
* Go for a slow stroll before bed - not enough to sweat, but enough to generate heat
Finally, any discussion of cold-weather sleeping would be lacking if the old hot water bottle trick wasn’t brought up. It can make a big difference on a cold night. Before going to sleep, and while the stove is still running, simply boil a liter of water and fill the bottle. Dry it off and slip it into the sleeping bag for a jump start on a cold night. And this provides plenty of water to drink on those long, dark nights. Just be sure to take it out of the bag when it cools to body temperature or below so body heat isn’t being used to keep it warm. A bottle like this, tucked into a bag/mat system described above (highly insulated) will last well into a winter’s night. Cheating? You bet!