A bivouac shelter or bivvy is any of a variety of improvised camp site or shelter that is usually of a temporary nature, used especially by soldiers or people engaged in backpacking, bikepacking, scouting or mountain climbing. It may often refer to sleeping in the open with a bivouac sack, but it may also refer to a shelter constructed of natural materials like a structure of branches to form a frame, which is then covered with leaves, ferns and similar material for waterproofing and duff for insulation. Modern bivouacs often involve the use of one- or two-person tents but may also be without tents or full cover. In modern mountaineering the nature of the bivouac shelter will depend on the level of preparedness, in particular whether existing camping and outdoor gear may be incorporated into the shelter.

Backpacking is the outdoor recreation of carrying gear on one's back while hiking for more than a day. It is often an extended journey and may involve camping outdoors. In North America, tenting is common, where simple shelters and mountain huts, widely found in Europe, are rare. In New Zealand, hiking is called tramping, and tents are used alongside a nationwide network of huts. Hill walking is equivalent in Britain, though backpackers make use of a variety of accommodation, in addition to camping. Backpackers use simple huts in South Africa. Trekking and bushwalking are other words used to describe such multi-day trips.