In those kinds of situations, it would be wise to know as many quick and simple ways to find water, build fire and shelter, gather food and otherwise provide for your necessities if/when you are cut off from civilization.

The Primitive Technology channel on YouTube has taken things pretty far, and it might be good information to know and master for yourself.

via Primitive Technology:

I built this hut in the bush using naturally occurring materials and primitive tools. The hut is 2m wide and 2m long, the side walls are 1m high and the ridge line (highest point) is 2m high giving a roof angle of 45 degrees. A bed was built inside and it takes up a little less than half the hut. The tools used were a stone hand axe to chop wood, fire sticks to make fire, a digging stick for digging and clay pots to carry water.