Every emergency kit should have emergency blankets, and they are a very smart idea for backpackers and hikers to keep in their packs as well. This silver blanket will keep up to 80% of your body's heat and is waterproof and windproof. It is engineered to reflect and retain heat, which, in an emergency, could be a lifesaver. The blanket unfolds to 4.6' x 7.2' yet folds small enough to fit in your pocket or the glove compartment.