how to build a survival snow cave
Amsnow
The all-snow igloo
A second type of snow cave resembles an igloo. Again, when snow is rapidly and vigorously moved, it creates friction. This friction causes the snow to melt, ever so slightly, and once settled, the snow compacts hard.
With the proper tools or makeshift tools, shovel the snow into a mound- build it long enough that a body can lay prone and tall enough that one can kneel. Pack the snow as you dig. Once the mound is constructed, dig down at an angle, under the mound, a three-foot long entrance hole. Make it only wide enough to slither in. The sloped entrance keeps wind and cold from pouring in and heat from escaping.
Once the entrance hole is bored out, begin excavating the snow under the mound's roof. The hardened snow, will hold its weight with ease. Leave about a foot of snow above your head. Think of this as an igloo - round outside, rounded out on the inside. Place the excavated snow in front of the entrance as a wall or wind break.
Punch a breathing hole through the cave's ceiling. Cover the entry with tree branches or space blanket, if available.
For light and warmth, flame-up a survival candle. Again, make sure a breathing hole is available to exhaust the smoke and body-generated CO2. In either cave, inside temperatures will remain between 33 and 35 degrees- at a minimum- and a body can survive in this climate for a long time.
Outside the cave, build a signal fire and anchor down easily identifiable material on a tree or rock, such as a fluorescent orange vest, jacket, blanket or signal flag.
More simple advice,
Always keep a snow shovel and a ice/snow/wood saw in your snowmobile. Canadian company, Survival On Snow 780/973-5412, manufactures a light-weight snow shovel with an integrated saw inside the handle. Buy it, pack it, use it. These two tools can be your best on-site construction partners.
Don't dig with your hands unless you have no choice. Almost any tool - a ski, helmet face shield, even a pair of goggles - will be more efficient. Avoid exerting yourself to exhaustion - stay calm and conserve your energy. Additionally, working up a heavy sweat will cause more harm.
Don't wait until you are in an emergency situation to build your first snow cave. If you're preparing a deep-woods winter adventure, this practice may save your life.