"Man vs. Wild" host Bear Grylls speaks at the Television Critics Association Press Tour July 13, 2007, in Beverly Hills, Calif.

Frederick M. Brown/Stringer / Getty Images

Shelter Basics

When choosing a place to build your shelter, try to stay near a source of water. If your scenario is a crashed car or a small airplane, stay as close to the wreckage as is safe. If it's heavily shaded from view, stay close but visible. You should also avoid natural hazards like dead tress that could fall, cliffs and dry river beds. Heavy rains can turn a dry bed back into a rushing river very quickly. Your shelter should be no bigger than necessary -- the larger the shelter, the harder time you'll have holding in the heat.

If possible, don't sleep directly on the ground. Piling grass or pine needles can go a long way toward helping you retain body heat. Your shelter should be ventilated, especially if you plan on having a fire inside or near the entrance. Use large rocks or tree branches to block the door. This prevents heat from getting out and animals from getting in.

Let's say you swerved off the side of a mountain at night and can't reach the roadway. The most important thing is to make it through the night with a temporary emergency shelter. All you want to do is to provide some basic protection from the elements. If it's dry, you can simply dig a hole in the ground and cover it with large sticks, followed by smaller, dense boughs. Fir tree branches make excellent insulation from the cold. If it's raining or wet, avoid burrowing in a hole and get off the ground. If this isn't possible at the time, make cover on flat or sloped land so rainwater can drain.

Other ways to find emergency shelter:

  • Use fallen or standing hollow trees as sleeping burrows.
  • Get inside a cave or under an overhang to provide shelter from wind and rain.
  • Stay under dense tree branches to provide an instant canopy of thick cover.
  • Use boulders and large logs to break the wind.

Just remember, in an emergency your goal isn'­t comfort. It's to get through the night until you can assess your situation and build a proper shelter. It's also important to be careful whenever you're dealing with caves. Stay close to the mouth so you don't get lost and be very aware of other creatures seeking shelter alongside you.

­­In the next section, we'll look at how to build shelters with on-hand materials.

­