The entrance for the igloo is usually at the bottom, and includes at least one right angle, which keeps the high winds from blowing straight into the igloo and chilling the residents or blowing out the fire. They also all have a small hole on the top that keeps the smoke from building up inside the igloo. All of these factors take advantage of underlying physics, and the temperature inside an igloo is likely to be 20 degrees or so, while the outside temperature in northern regions can drop down to -50 degree Fahrenheit during the daytime. 20 degrees may not be what some consider to be comfortable, but a 70 degree difference is certainly welcome somewhere so cold.
Answered by: Frank DiBonaventuro, B.S., Air Force officer, Tinker AFB, OK.
'One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike - and yet it is the most precious thing we have.'