4. A giant fire can be an excellent snow country signal. Not only do the light and smoke signal for help, but the snow will melt in a circle around the fire. This can give you a large, round, dark patch of ground with a fire in the center. A low altitude plane or search helicopter should see that for sure. And in deep snow, you'll need to build a platform on top of the snow to effectively burn a fire. Using a "raft" of wet or green wood will give you several hours of burn time without the need to excavate snow down to the ground level.