The knowledge of which plants were edible and which were not, of where game was likely to be and how to take it efficiently, of how to read weather and terrain — this was not a supplement to survival.

It was survival.

Building shelter without conventional materials required understanding the properties of the materials available: snow as insulation, hides as wind barriers, the structural principles of winter shelters that Indigenous communities across the northern part of the continent had been using for thousands of years.

A properly constructed snow shelter is significantly warmer inside than outside because of the insulating properties of snow itself.

This is not intuitive to someone raised in European building traditions.