In deep snow with only a few supplies, the simplest and most efficient design is a snow cave or an A‑frame snow house. First find a slope where the wind blows downhill, dig a shallow pit, and pack the snow walls high. The entrance should be on the windward side so you’re protected from drafts. Use a tarp or old sleeping bag as a roof; lean it against the packed snow walls and secure it with a few branches or rocks. Line the inside with insulation – a thick sleeping pad or extra layers of clothing – to keep heat from escaping. Keep the opening small and close it at night with a snow door. It’s quick to build, uses the snow as natural insulation, and stays warm as long as you keep the interior dry. Just remember to stay away from the edges where the snow might collapse.

Snow’s a great insulator on its own, but a thin layer of cloth or even a few packed snow blocks inside the walls can cut the heat loss in half. It’s a quick tweak that adds a buffer against drafts. If wind starts to bite and the roof feels loose, just keep piling snow in front of the opening and around the roof edges. A heavier tarp or a simple rope tied to a branch on the inside can hold it in place. The key is keeping the entrance sealed and the roof weight steady; once the wind’s under control the cave stays warm.