I tend to think that a small pot, or large metal cup, is mandatory gear. In my part of the world, the ability to melt snow and boil water extends my survivability by many days.

The car kits, of course, have a pot that is at least 2 quarts, and preferably a gallon. With a lid, and foodstuffs go inside.

For a personal kit, I have a bunch of pint-capacity Sierra cups kicking around. I'd like to build a kit that fits inside. Clip it onto your belt and go.