To understand why igloo will not melt, you must first figure out how the igloo is built. Before building the igloo, you must first dig a large hole in the snow, almost half a person's depth, and then compress the snow into a turning shape, and then stack the bricks together to form a dome-shaped house. The gaps are also filled with snow. Finally, some furniture and daily necessities are put in, and an igloo is built.
Generally speaking, the Inuit can live in an igloo for about 2 months at most. The igloo is just a temporary place for them to stay during the hunting season and they will not live here for a long time. Someone has tested the insulation effect of the igloo. When it is minus 50°C outside, the temperature inside the house is about minus 20°C. Obviously, the igloo still has a certain effect of thermal insulation and cold protection. Snow houses can isolate strong winds. When cold wind blows over the surface of objects, especially the surface of the human body, a large amount of heat will be taken away. The thickness of the walls of snow houses is generally more than 50 centimeters, which is not only very strong, but also has a good windproof and thermal insulation effect. Snow will not absorb heat as long as it does not melt, and snow will only melt at 0°C. The temperature where the Inuit live is below 0°C all year round. Under such climate conditions, it is difficult for snow to melt.
In addition, the wall made of snow bricks also has a good function of reflecting heat. We can understand that the human body itself is a small heat source. Our body will continue to radiate heat to the outside under normal circumstances. When living in an igloo, part of the heat emitted by the human body will be reflected by the snow wall and return to the body, so the temperature inside the house will be higher than outside.
Of course, the Inuit not only rely on their own heat radiation to stay warm, they also "light fires" in the house, but this fire is different from what we understand. They light not firewood, but oil lamps. The oil in the oil lamps comes from the fat of seals, whales and other animals. This kind of oil is very precious and is usually not used to make fires for cooking, but only for lighting. The heat generated by grease is not comparable to the heat generated by burning firewood, and it is completely unable to heat the snow to a temperature that can melt it.
Snow houses are not completely sealed. There are usually gaps or vents on the roof. Otherwise, if animal fat is burned for a long time, the air in the house will become turbid. Hot air is less dense than cold air, so it will float out through the gaps or vents in the roof and will not stay in the house for a long time. In this way, the temperature inside the house can be maintained at about a few degrees below zero, and the house will not melt.
A few degrees below zero may still be very cold for us, but for the Inuit people who live in the Arctic all year round, it is just right. The extremely cold weather and scarce food resources have also allowed them to evolve stronger bodies. The food we usually eat is mainly cooked food, and vitamins are mainly obtained from fruits and vegetables. The Inuit do not cook. Heating will destroy the vitamins in the food. Most of the time, they eat raw meat and get the vitamins they need from the raw meat (the notorious pickled puffin). Although their physical fitness is excellent, allowing them to withstand the polar cold, the harsh environment still makes their average life span very short, and the survival rate of newborns is also very low.
Nowadays, many Inuit people have given up this primitive hunting life without a fixed residence. Most of them choose to live in fixed villages and live a modern life. Only a few people still insist on the traditional igloo custom.
