Igloo
An igloo (or iglu) is a shelter (a place for people to stay warm and dry) made from blocks of snow placed on top of each other, often in the shape of a dome (like half of a hollow ball). They were used in winter as temporary shelters by hunters when they were away from their regular homes.
They were most often built in places where a lot of snow covers the land for weeks or months at a time, such as the far north of Canada and Greenland. Most igloos are built by native Inuit people (sometimes called Eskimoes). As they learned to build them better, sometimes people would build larger igloos that would last longer and hold more people, even for dancing.
The word Igloo comes from the Inuit Indian word for home. While often made from snow, an igloo can be made out of wood, stone, or even cement. The snow and ice function as insulators to trap body heat in the igloo. It is the people inside the igloo that provide the actual heat from their own body, similar to how a furnace warms up a house.
Eventually, the snow will melt inside an igloo when people are in it. However, once the people leave, the melted water freezes and turns to ice, which actually makes the igloo walls stronger. Over time this adds a lot of strength to the igloo. Igloos can only be built in places and at times, like during winter that will freeze water or they would melt in the sun.
Snow igloos are constructed with large blocks of dry hard snow that leans inward to form a dome. The entrance is most often below ground to keep out the wind. The entrance to an igloo can usually just fit one person at a time. However, they can be build to hold dozens of people inside it.
