How Igloos Turn Snow into Toasty Havens

An igloo is made of compressed snow. Compact hardened snow is a great insulator of heat because snow is nothing but semi-frozen water with roughly 95% trapped air. The air molecules trapped between the tiny ice crystals create air pockets, which act as excellent insulators that prevent heat loss due to convection. Thus, snow is the perfect material to build a warm abode in the form of an igloo amidst the freezing Arctic environment.

The type of snow used is equally important. Freshly fallen snow is brittle and powdery and cannot be used to build a sturdy structure. Thus, igloos are made by cutting out hardened, compressed snow blocks from the ground. An experienced Inuit can build an igloo from scratch in almost an hour. All it takes is a saw, snow, and plenty of skill and technique.