Snow cave

It has thermal properties similar to an igloo and is particularly effective at providing protection from wind as well as low temperatures.

A narrow entrance tunnel, a little wider than the occupants of the cave, leads into the main chamber which consists of a flat area, perhaps with elevated sleeping platforms, also excavated from snow.

Most sources agree that using tools such as a strong plastic or metal shovel, and maybe ice axe, is vital; digging by hand is for emergencies only.

A length-wise pit may be dug deeper into the cave floor to provide a place for the coldest air to gather, away from the occupants.

This is thought to result in reduced air ventilation through the snow cave walls and roof, and thus increase the risk of suffocation.