Which detail from "To Build a Fire" best supports the idea that survival was not guaranteed along the actual Yukon trail?

Then it turned and trotted up the trail in the direction of the camp it knew where were the other food providers and
fire providers

His pace of four miles an hour had kept his heart pumping blood to the surface of his body and to all the
extremities.

But he was safe. Toes and nose and cheeks would be only touched by the frost for the fire was beginning to burn

A good idea, he thought, to sleep off to death. It was like taking an anesthetic Freezing was not so bad as people
thought