In the End of the Extreme Cold, Everyone's Shelters Are Very Different

Story background: A sudden extreme cold disaster enveloped the world. The originally normal climate was just a light rain at the beginning. The light rain continued for half a month. At first, people were not worried about it. Until the violent storm overnight turned cold and the temperature plummeted to tens of degrees below zero. The snowstorm raged. The infrastructure was paralyzed in just two days. The social order collapsed. Humanity was instantly plunged into an existential crisis.