Survival cards are very useful, indeed. I use a standard pack of Bicycle cards, but remove the jokers to save weight.

When lost, I immediately find a a flat space and lay out a spread of Solitaire. This short circuits the fight-or-flight catecholamine storm described in DR's excellent post above.

And soon enough, a stranger will walk up and tell me to play the red three on the black four. Then I follow the stranger to safety.

No matter how remote the site, there is something about a Solitaire game that attracts kibitzers.