Another $.02 worth:

I have put a lot of thought into the shelter aspect of a PSK. Think about the rule of 3s. In three hours you can die from hypothermia. It would seem to be the most important thing next to a cool head and a first-aid kit.

Rule of 3s: in 3 seconds you can do something foolish, in 3 minutes you can die from lack of oxygen to the brain, in 3 hours you can die from lack of thermo-regulation, in 3 days you can die from lack of hydration, in 3 weeks you can die from lack of nutrition.

The question is: how big can it be? What is your container? What are you carrying it in? For a small pocket size PSK all you can carry is cord to tie some wood together to make a shelter out of whatever you can find. If you have a fanny pack, a CamelBack, or a daypack then you can carry something more comfortable. There is still the question of how much are you really willing to carry, all the time, when you know that you could not possible need it “this time.” In the book “98.6” Cody suggests a heavy-duty Space blanket, a regular Space Blanket, and trash bags. If the goal is to stay warm then a neckerchief, gloves, and a nightcap could help greatly in keeping you warm. A trash bag can be filled with leaves and grass and used as a blanket.

That said, I carry a CamelBack with PSK items. My shelter is a heavy duty Space Blanket for the top. I take one cord and 6 small steel stakes. Tie the cord to anything about chest high. Walk about 4 steps into the wind and hammer in the stake and tie the cord to it. You now have a single cord going from something to the ground. I then hook a grommet of the space blanket around the stake. I then pull the farthest corner up the cord and secure it in place by pulling the cord though the grommet and using a stick or another stake to hold it in place by friction. You now have a wedge or taco shape. I then stake down the corners and sides of the HD Space Blanket. I then take the small space blanket or a large trash bag and put that on the ground under the HD Space Blanket. I tuck the ends up so that water will run under the plastic. I then tie some orange plastic marker tape on the cord so that water will drip down the tape instead of coming into the shelter. It is big enough to sit up in and long enough to lie down in. A reflector fire will get the inside warm. The above mentioned trash bag can be used as a blanket. A big trash bag can be substituted for the small Space Blanket and will probably be more useful. But it is bigger! Just throwing the heavy duty Space Blanket on the ground and lying on it and pulling it over you like a blanket works OK too. Several Boy Scouts in our troop sleep like that with a cheap blue tarp.