A large debris bed is what we typically use on our survival courses in the mountains when it’s too dry for a shelter and fire combo. This is made by piling up a large mound of pine-needles, leaves, moss, cattails. By large mound, I mean at least waist-high and a few feet longer than your height. We’ve used this kind of shelter on my survival courses down to 10 degrees F at night with just the (wool) clothes on our backs. Ideally, you should make a framework of to contain the debris, but a large mound will suffice otherwise. Once the pile of debris is in place, hollow out a trough large enough for your body and then climb in and lay down. Pull in a thick layer of debris around you until you are enveloped with only your face showing.
Tony Nester
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This kind of shelter comes into play when it is too dangerous to have a fire or perhaps injury is preventing you from making a more elaborate shelter and collecting firewood. The latter was the case with one downed pilot who crashed in the Sierras in the 1990s. With a broken body—shattered ankle, shoulder and ribs—this intrepid soul hobbled out on foot over 12 bone-chilling days, each night building a pine-needle bed for warmth. You can read more about it in the book Survive! by .
Stories abound of actual survivors who have done the “scarecrow” method of stuffing their pants, sleeves, and shirts with leaves so they can survive sub-freezing nights. Use the survival tool between your ears, and if all else fails, think like a squirrel.