What can I use for an emergency shelter?

If you are in a car or plane, staying inside isn't necessarily the best choice for shelter. The interior is good protection from the rain but not from the cold. The large interior is difficult for you body to heat. A well-built natural shelter may be much better, especially if you can build a fire nearby. If you do stay in the car or plane, put as much clothing on as possible, cover yourself with blankets, and pull you feet up onto the seat since the floor is the coldest area. If you are looking for protection from the heat, sitting outside in the shade is probably your best choice.

In the snow, find a large tree with branches hanging to the ground. Dig out an area large enough to sit with your back against the tree. If you can not find a well suited tree, try a large snowdrift. In either case, dig the opening lower than the sitting area. This will trap the warm air inside. Place dry leaves or other material where you are going to sit for insulation. Poke a ventilation hole in the roof. There is a very real risk of suffocation without this hole. Light a candle if you have one.

If you are in an area without snow, build a teepee large enough to sit in. The smaller it is, the easier it is to build and heat with your body. Tie three sticks together to form a tripod. Use a shoe string if you did not bring rope or chord (cut the other shoe string in half and use on both shoes). Lay more sticks onto the tripod. Cover with a large pile of leaves, pine needles, or shrubs. Build a fire near the opening if you can do so safely.

If there are no sticks for building a teepee, build a large pile of leaves or pine needles then burrow into it.