Constructing an igloo

The snow used to construct an igloo must have enough structural potency to be cut and stacked in the suitable manner. The best snow to use for this reason is snow which has been blown by wind, which can serve to compact and interlock the ice crystals. The opening left in the snow where the blocks are cut from is generally used as the lower half of the shelter. Sometimes, a short tunnel is constructed at the entrance to reduce wind and heat loss when the door is opened. Due to snow's outstanding insulating properties, inhabited igloos are surprisingly comfortable inside. In some cases a single block of ice was inserted to permit light into the igloo.