2nd Priority is shelter. 3 days without water. 3rd Priority is water. 3 weeks without food. 4th Priority is food.
Trash bags make good temporary shelter.
Hollowed out logs, if big enough make good shelter. Caves or rock overhangs provide shelter. When seeking shelter make sure you are at least 100 ft. from water, because of insects. Make sure your shelter faces the south to avoid the north wind in cold climates. Watch for over-hanging tree limbs that could break off and fall on your shelter and injure you.