igloo

An igloo is a type of shelter built from blocks of snow, typically in a dome shape. Historically, igloos were used by the Inuit people of the Arctic regions, particularly in areas where suitable snow conditions were available and trees were scarce. The construction of an igloo involves carefully cutting and stacking snow blocks, often with a spiraling technique to create a stable structure. The interior is designed to trap body heat and the heat from a small lamp or stove, making it surprisingly warm and livable despite the frigid exterior temperatures.

The effectiveness of an igloo as a shelter comes from the insulating properties of compacted snow. The snow traps air, which acts as an insulator, preventing heat from escaping and keeping the interior significantly warmer than the outside. A well-constructed igloo can maintain an internal temperature above freezing, even when external temperatures are well below zero. Modern igloos, while less common as primary residences, are still sometimes used by Inuit hunters for temporary shelter during long trips, and the design has also inspired recreational snow shelters built by campers and winter sports enthusiasts. The word "igloo" itself comes from the Inuktitut word for house.