Wilderness Survival photo

When a man is faced with spending an unexpected night outdoors, his gut reaction is to pat his pockets for matches. Besides providing warmth, a fire’s cheerful light is an antidote to the spiritual pall that accompanies the fall of darkness. But in heavy snow, when deadfall is buried and wet, a fire can be hard to spark and difficult to maintain. At such times, your best option is to use the snow to your advantage.

Snow not only provides a windbreak but is one of nature’s best insulators. A properly constructed shelter made with it can raise inside air temperatures to above freezing on a 20-below day–and it can get even warmer if you light a candle (be sure to vent carbon monoxide with airholes). The key is to keep the inside volume small, so that your body heat can warm the space. The roomier your retreat, the colder and more miserable you will be. Here are two shelters for different situations.

Snow Trench

The snow trench is the quickest, easiest shelter to build. It’s the best choice if you don’t have a shovel, where snow cover is light, or if the day is on the wane.

[STEP ONE] Using a snowshoe or flat piece of wood, excavate a trench that is 3 feet deep, 7 feet long, and several inches wider than your shoulders. In snowpack of less than 3 feet, build up the depth of the trench with walls shoveled from nearby drifts.

[STEP TWO] Cover the bottom of the trench with pine boughs for insulation.

[STEP THREE] Place tree limbs, skis, or poles across the top of the trench, leaving space at one end for entry. Fill in any gaps with smaller limbs, spread a tarp over the shelter if you have one, then pile up a foot of snow. Alternatively, cut rectangular blocks from consolidated snow and tilt the short edges against each other to form an A-frame roof.

[STEP FOUR] Block the entry with your pack or make a door by folding snow inside a tarp or stuffing it inside a plastic garbage bag.

Quinzee or Snow Hut

The Quinzee is the poor man’s igloo. It is easy to build, provided that you have enough gear or brush to create a circular mound, but you must wait for the disturbed snow to “set up” or harden before you can excavate these living quarters.

[STEP ONE] Pile your pack and other gear into the rough shape of a mound. In lieu of a duffel, improvise by heaping up brush. Cover it with a tarp or poncho.

[STEP TWO] Bury the mound with snow to a depth of 2 feet, tamping it lightly to hasten consolidation. Wait until the snow sets up before proceeding, which can take from 30 minutes to three hours.

[STEP THREE] Dig an entrance into the mound, angling down to create a cold air sump, then up into the center. To expedite snow removal, dig into the far side also (you’ll cover this opening back over with snow when completed). Remove the tarp and gear.

[STEP FOUR] Hollow out the interior until the walls are a foot thick (use a stick to gauge this). Pat the snow on the inner walls smooth. If you have a candle, let it burn inside to create a glaze, then put it out so that the surface refreezes. This will keep the Quinzee from melting when you bring the candle back in for warmth. Pile pine boughs to insulate the bedding area and use your pack for a door or make one out of a snow block.

[STEP FIVE] Drill an airhole through the wall 2 inches in diameter to vent carbon monoxide buildup. This is of critical importance for any snow shelter.

A survival candle can heat the inside of a snow shelter or help start a fire. You can use a plumber’s candle, found in any hardware store. An even better solution is Coghlan’s three-wick survival candle, which comes in a tin about the size of a can of shoe polish. It can burn for 36 hours and weighs 6 ounces. $4; 877-264-4526; www.coghlans.com –K.M.