If you are in a wooded area and have enough natural materials, you can make a field-expedient lean-to without the aid of tools or with only a knife. It takes longer to make this type of shelter than it does to make other types but it will protect you from the elements.
You will need two trees (or upright poles) about 2 meters apart; one pole about 2 meters long and 2.5 centimeters in diameter; five to eight poles about 3 meters long and 2.5 centimeters in diameter for beams; cord or vines for securing the horizontal support to the trees; and other poles, saplings or vines to crisscross the beams.
To make this lean-to —
* Tie the 2-meter pole to the two trees at waist to chest height. This is the horizontal support. If a standing tree is not available, construct a bipod using shaped sticks or two tripods.
* Place one end of the beams (3-meter poles) on one side of the horizontal support. As with all lean-to type shelters, be sure to place the lean-to's backside into the wind.
* Crisscross saplings or vines on the beams.
* Cover the framework with brush, leaves, pine needles or grass, starting at the bottom and working your way up like shingling.
* Place straw, leaves, pine needles or grass inside the shelter for bedding.
In cold weather, add to your lean-to's comfort by building a fire reflector wall. Drive four 1.5-meter-long stakes into the ground to support the wall. Stack green logs on top of one another between the support stakes. Form two rows of stacked logs to create an inner space within the wall that you can fill with dirt. This action not only strengthens the wall but makes it more heat reflective. Bind the top of the support stakes so that the green logs and dirt will stay in place.
With just a little more effort you can have a drying rack. Cut a few 2-centimeter-diameter poles (length depends on the distance between the lean-to's horizontal support and the top of the fire reflector wall). Lay one end of the poles on the lean-to support and the other end on top of the reflector wall. Place and tie into place smaller sticks across these poles. You now have a place to dry clothes, meat or fish.
In a marsh or swamp, or any area with standing water or continually wet ground, the swamp bed keeps you out of the water. When selecting such a site, consider the weather, wind, tides and available materials.
To make a swamp bed —
* Look for four trees clustered in a rectangle, or cut four poles (bamboo is ideal) and drive them firmly into the ground so they form a rectangle. They should be far enough apart and strong enough to support your height and weight, to include equipment.
* Cut two poles that span the width of the rectangle. They, too, must be strong enough to support your weight.
Secure these two poles to the trees (or poles). Be sure they are high enough above the ground or water to allow for tides and high water.
* Cut additional poles that span the rectangle's length. Lay them across the two side poles and secure them.
* Cover the top of the bed frame with broad leaves or grass to form a soft sleeping surface.
* Build a fire pad by laying clay, silt or mud on one comer of the swamp bed and allow it to dry.
Another shelter designed to get you above and out of the water or wet ground uses the same rectangular configuration as the swamp bed. You very simply lay sticks and branches lengthwise on the inside of the trees (or poles) until there is enough material to raise the sleeping surface above the water level.
Do not overlook natural formations that provide shelter. Examples are caves, rocky crevices, clumps of bushes, small depressions, large rocks on leeward sides of hills, large trees with low-hanging limbs and fallen trees with thick branches. However, when selecting a natural formation —
* Stay away from low ground such as ravines, narrow valleys or creek beds. Low areas collect the heavy cold air at night and thus are colder than the surrounding high ground. Thick, brushy, low ground also harbors more insects.
* Check for poisonous snakes, ticks, mites, scorpions and stinging ants.
* Look for loose rocks, dead limbs, coconuts or other natural growth that could fall on your shelter.