The Importance of Shelter
Shelter is necessary to give shade, to repel wind and rain and to keep in warmth. Sleep and adequate rest are essential and the time and effort you put into making your shelter comfortable will make them easier to get. If you are the victim of a plane crash or a vehicle breakdown, either may provide a shelter or materials from which one can be built – but if there is fire or the threat of the fuel tank exploding, wait until it has burned out before attempting salvage.
If you are an unequipped victim of an accident, are trapped by unexpected fog or caught by nightfall in terrain where it is not safe to move around, or if exhaustion or injury prevents you from going further, you may have to make do with any natural shelter that you can find for the night, or until you can more fully assess the situation. In this case, virtually any protection from wind, rain and cold will be welcome. If movement down a slope seems risky, traversing even a short way along the contour may bring you out of the wind. If no cave or crevice is available to give shelter, make use of any hollow in the ground. Add to its height, if you can, by piling up rocks – but make sure that any structure is stable and use a backpack, if you have one, to increase the windshield before settling down on the leeward side.
If there is still daylight to see by, and you have no injuries to handicap you and are not isolated by un-negotiable cliffs or other barriers, it will be worth seeking possible better places in the vicinity. For a long-term place to shelter you should find a secure site with convenient access to your major needs.