How an Igloo Actually Works

An igloo is a snow shelter built in Canada's Central Arctic and Greenland. Snow insulates the interior.

Air pockets trapped inside the snow act as insulation. Outside temperatures drop to minus forty-five degrees Celsius.

Workers cut snow bricks into five- or six-sided shapes so they interlock tightly.

The dome follows a catenary curve resembling a paraboloid. This shape keeps pressures compressive as snow ages.

A short entrance tunnel reduces wind and heat loss when the door opens. The lower floor is essentially a cold-air moat.

Igloo comes in small temporary, medium family, and large grouped forms.

Central Inuit around the Davis Strait lined living areas with skin. Central heating, powered entirely by sitting still.

A qulliq stone lamp melted walls slightly right after construction. Refreezing added strength. Open-concept living, strictly seasonal.