An Igloo (冰屋) is a traditional Arctic snow shelter developed by the Inuit (因紐特人,舊稱「Eskimo 愛斯基摩人」), built from blocks of hard-packed snow arranged in a spiraling dome that distributes weight evenly and resists strong winds. Although made of snow, the structure stays relatively warm because snow acts as a natural insulator, trapping heat from body warmth or small lamps while blocking freezing winds outside. Igloos are also designed with a low tunnel entrance, allowing cold air to sink below the raised living platform so the interior remains warmer.