Whether in an emergency or by choice, building a winter shelter is an essential skill for any mountaineer or free-rider. Relatively easy to construct, a snow cave is the most popular option. For experienced outdoor enthusiasts, learning to build one is a great microadventure idea, suitable for the whole family, a romantic date, or a solitary minibreak from civilization.
Know your basics
Building a snow cave is a few hours of effort that requires a lot of energy. In addition, it is practically impossible to succeed without a shovel (an avalanche shovel will do just fine) and a snow saw is a bonus. Insulating the body from the snow is essential to prevent potentially deadly heat loss, as is creating a ventilation hole. Without it, carbon monoxide and dioxide poisoning is a serious risk. If you set up a candle in your snow cave, not only will it raise the temperature, but the flickering flame will act as a warning sign against noxious gases.
Choose the location
Search for wet, packable snow. The ideal location for a snow cave is a hillside safe from avalanche risk where the wind has piled up snowdrifts to around five feet in depth. You can always pile up more snow if there isn’t enough, or if you want a bigger shelter.
Make an entrance tunnel
Slightly wider than your body, the entrance to the snow cave must be located below the main chamber. From the entrance, dig out a tunnel on a slight slant upward, aiming for the ideal length of around eight feet.
Situating the entrance downwind can provide further protection from stormy weather.
Build the sleeping chamber
Shaping the sleeping area as a dome with a rounded roof and steep walls will prevent the melting snow from dripping on its inhabitants. Depending on the situation, you can make the snow cave as basic or elaborate as required, from a simple survival shelter to a roomy suite with shelves and benches.
Creating an elevated sleeping platform will raise your body closer to the top of the chamber where the air is warmer.
The most important design feature is building the main chamber well above the entrance so that the snow cave traps body heat.
Once the snow consolidates under its own weight, remember to poke out ventilation holes in the ceiling of the snow cave with a stick or a skiing pole. If possible, mark the location of your snow cave from the outside to prevent anybody from walking on it, or in case of an emergency.
Enjoy the night
Once you are happy with your shelter, it is time to move in. Ideally, the snow cave should be big enough to accommodate all of your gear and it is essential to always have your snow shovel by your side.
A properly built snow cave will maintain a temperature of around 32 °F (0 °C), even when outside temperature drops as low as negative forty. In an emergency, spending the night on an emptied backpack will prevent hypothermia and save a life, but if you bring your warmest camping set up, a stove and a bottle of wine, the humble snow cave can be one of nature’s most luxurious lodgings.