Space Blanket

A space blanket (also known as a mylar blanket, emergency blanket, first aid blanket, safety blanket, thermal blanket, weather blanket, heat sheet, or shock blanket) is an especially low-weight, low-bulk blanket made of heat-reflective thin plastic sheeting.

They are used on the exterior surfaces of spacecraft for thermal control, as well as by people.

But we're not here to talk about space, we're here to talk about survival, but let's be real here - if it's good enough for a space ship, its good enough for us.

Their compact size before unfurling and light weight makes them ideal when space or weight are at a premium. They may be included infirst aid kits and also in camping equipment. Lost campers and hikers have an additional possible benefit: the metallic surface appearance flashes in the sun, allowing use as an improvised Distress beacon for search and rescue, and also as a method of signalling over long distances.

Keep one of these large blankets in your kit, and be prepared for the worst.