Some igloos are only a temporary shelter -- a few hours or days' protection, while others may be larger and used for a longer term. Larger igloos may include public spaces and multiple rooms for more than one family.
Although snow is cold, it is also a good insulator. Inside an igloo it can be reasonably warm and comfortable -- as warm as 16 °C (61 °F) heated by just body heat. The interior may be lined with skins and may also form an ice lining by the mix of heat inside and refreezing from the cold outside.