An igloo (Inuit language: iglu,Inuktitut syllabics: ᐃᒡᓗ, plural: iglooit or igluit) or snowhouse is a type of shelter built of snow, originally built by the Inuit.

Although igloos are usually associated with all Inuit, they were predominantly constructed by people of Canada's Central Arctic and Greenland's Thule area. Other Inuit people tended to use snow to insulate their houses, which were constructed from whalebone and hides. Snow is used because the air pockets trapped in it make it an insulator. On the outside, temperatures may be as low as −45 °C (−49 °F), but on the inside the temperature may range from −7 °C (19 °F) to 16 °C (61 °F) when warmed by body heat alone.

The Inuit word iglu (plural igluit) can be used for a house or home built of any material, and is not restricted exclusively to snowhouses (called specifically igluvijaq, plural igluvijait), but includes traditional tents, sod houses, homes constructed of driftwood and modern buildings. Several dialects throughout the Canadian Arctic (Siglitun, Inuinnaqtun, Natsilingmiutut, Kivalliq, North Baffin) use iglu for all buildings, including snowhouses, and it is the term used by the Government of Nunavut. An exception to this is the dialect used in the Igloolik region. Iglu is used for other buildings, while igluvijaq, (plural igluvijait, Inuktitut syllabics: ᐃᒡᓗᕕᔭᖅ) is specifically used for a snowhouse. Outside Inuit society, however, "igloo" refers exclusively to shelters constructed from blocks of compacted snow, generally in the form of a dome.

Raymond Paul "Ray" Mears (born 7 February 1964) is an English woodsman, instructor, author and TV presenter. His TV appearances cover bushcraft and survival techniques, and he is best known for the TV series Ray Mears' Bushcraft, Ray Mears' World of Survival, Extreme Survival, Survival with Ray Mears, Wild Britain with Ray Mears and Ray Mears Goes Walkabout.

Mears grew up in Kenley, Greater London, and the North Downs, where he discovered a countryside abundant with wildlife. Educated at Reigate Grammar School, a co-educational independent school in Reigate, Surrey, he learned to track foxes in the forest at a young age. As a boy, he desired to sleep out on the trail, but unable to afford camping equipment, he resorted to setting up camp using what he could find in his surroundings.

Mears's enthusiasm for his subject, combined with his broad knowledge of survival and the uses which may be made of plants, trees and other natural materials found in woodland, forest or desert, have made him a popular figure in TV broadcasting in the UK.^{[citation needed]} He has travelled extensively across the world for his TV series and has learned survival techniques from the indigenous peoples he has met. In his programmes he demonstrates his knowledge of the wild, how to find food from seeds, berries, roots and other growing things, and how to survive by constructing temporary shelters, fires and canoes from natural materials.