Building improvised shelters from the elements is not hard and can save your life. If you get too hot or too cold, you can die. Finding good improvised shelter can help you keep a normal body temperature. Shelter will help keep you dry and out of the wind or sun.
If you have a vehicle with you, you can utilize it for shade or shelter. If you are in the desert, the vehicle may become too hot during the day. You may be better off sitting next to it for shade. Remove a car seat and use it to keep you off the hot ground.
In hot weather, ground level is the hottest place. Try to get below or above the ground level. Dig a hole; build a seat or a hammock.
If there is natural shelter such as a cave, fallen tree, hollow log, rock overhang, or brush, take advantage of it, but watch for animals.
In cold weather, you can add insulation by stuffing your clothes with dry grass, leaves or carpeting from your vehicle. Just be sure it is dry and insect free.
If it is cold use leaves, grass, tree boughs, pine needles, or anything else you can think of to insulate you from the ground. The rule for staying warm is to put 2/3 of the insulation underneath you and 1/3 on top.
Low areas like valleys can be colder in the winter. It can be several degrees warmer if you just walk uphill a short distance.
Share warmth; do not be afraid to huddle together. Plastic bags, plastic sheets, or space blankets do not breathe. If you wrap them about you too tightly, they will trap moisture. Do not wrap plastic about your head as it can suffocate you.
If you are forced to sit in a confined area like a snow cave, do isometric exercises (tension exercises). This will increase your body heat.
In the following diagram, a shelter from the wind, an insulated bed of leaves, pine needles, boughs, a fire, and a reflector will help you stay alive.
Tree well shelter – A simple quick shelter that is easy to make. First, find a thick sturdy tree in deep snow. Conifers work best.
Then dig a hole in the snow near the tree’s base using whatever you have available including your hands. Try to make the hole at least 4 feet deep. The lower branches of the tree should form an overhead shelter when you are finished.
If the snow is not deep enough to form a roof, gather up branches and use them to make a roof. Pile snow on top of the branches to complete the roof.
Use other branches, pine needles and leaves to create insulation in your shelter by lining the bottom, and perhaps the sides, with them.
When you lay down for the night, curl up in a fetal position, to preserve warmth. Working hard creating the tree well shelter should have warmed you up. You will take that warmth with you into your shelter. Be careful during the construction to not sweat or get wet.
Snow Caves – Find a site on the lee side of a hill. Snow caves can be created quickly by digging into a snow bank or drift. Dig a compartment so that it is at least large enough inside for you to sit upright. Place your pack or a block of snow in front of the entrance hole. Use evergreen boughs or other natural materials to insulate yourself from the ground.
You can use a candle or build a very small fire in a snow cave. This requires a vent hole for adequate ventilation. If you have a problem with dripping water, your fire may be too large. Smoothing the inside of the roof helps to stop dripping, the water will then run down the side to the bottom of the cave.
If you think people will be out looking for you, make the site as visible as possible from the ground and the air. Place clothing, sticks or stomp an unusual pattern in the snow. When you are inside the cave your ability to hear what is happening outside will be reduced to almost nothing.
A properly made snow cave can be 32 °F or warmer inside, even when outside temperatures are −40 °F. Remember to stay dry while building your cave, if you start to sweat it takes a long time to dry out and can lead to hypothermia.
There are many things that you can carry with you to use to help build an improvised shelter, they include a knife, ax and 550 cord. One of the handiest things that I have found is cable ties. They are great to use in building a framework for your shelter. Here is a link to an article on them. Cable Ties a Great Survival Tool.
Just remember that whatever kind of shelter you are building the main idea is to keep your body temperature as near normal as possible.