Shelter:

Shelter: Create or find a shelter and then as quickly as possible move to or create a better shelter. Exposure to the elements can kill in a hurry. Under some conditions shelter will move up the list past fire. The rule of threes claims that in extreme conditions (especially exposure to extreme heat or extreme cold)s you can live for about three hours without shelter.

Your shelter should protect you from wind and percipitation, insulate you from the ground, and avoid natural threats (such as flash floods, insect mounds, and cliffs). You want the shelter to be in a location that provides easy access to water, building materials, fire wood, and other basic survival supplies.

Shelter:

You need shelter. The order of needs in the wild are immediate health dangers, shelter, water, and eventually food. Tents are the traditional answer. You need rope and usually tent pegs and a tens pole. Your tent pole can double as your walking stick. Maybe even use a quarterstaff as your tent pole/walking stick.

Tarps can be effective even as rain shelter and weight much less. You need rope or guylines and either trees of stakes and pole.

Ultralight hammocks are even lighter. You can get bug nets and rainflies for your hammock. Again the walking stick/tent pole/quarterstaff idea. Maybe use your spear as a walking stick/tent pole. You need the guylines and probably pegs as well.