Question

why a house made up of ice does not melt in the tundra region and keeps the eskimos warm?

Answer 1

In Tundra regions, the temperature is very low that prevents melting of houses called igloos made of ice.
Although igloos are made up of ice, Eskimos stay warm inside because their body heat warms the air inside the igloos and the air inside becomes warmer than the air outside. Both air and ice are good insulators and reduce heat loss from inside the igloos to the surroundings.