The thickness of your emergency blanket is something to consider carefully. Thicker designs will definitely make a better emergency shelter, but you can cut thinner sheets into strips should you need to fashion a rope, make a sling for a dislocated shoulder, or tie off a splint. Thick blankets are a better choice if you want to put a barrier up on one side of a fire to block the wind and reflect heat back at you in a survival situation, but thinner sheets may be easier to cut reflective strips from to make fishing lures or even cook a piece of meat next to the fire (never on the fire) should the need arise. Fortunately, emergency blankets are relatively inexpensive so you can get both types. Keep a thick version in the “go-bag” of your vehicle but carry a thin version in your daypack.