What happens to the man that provides the turning point in the story?
The turning point in the story comes when the unnamed protagonist breaks through the ice and gets soaked up to his knees. He has to build a fire to dry out and keep from having his feet and lower legs permanently injured by the ice. Up to this point he has felt confident, even though he had been warned not to travel alone when the temperature was lower than fifty degrees below zero. (He estimates that the actual temperature must be at least seventy below zero.) He feels some contempt for the old-timers and thinks of them as being "rather womanish." He gets his fire burning--but he has made the serious mistake of building it under a snow-laden spruce tree.
No wind had blown for weeks, and each bough was fully freighted. Each time he had pulled a twig he had communicated a slight agitation to the tree—an imperceptible agitation, so far as he was concerned, but an agitation sufficient to bring about the disaster. High up in the tree one bough capsized its load of snow. This fell on the boughs beneath, capsizing them. This process continued, spreading out and involving the whole tree. It grew like an avalanche, and it descended without warning upon the man and the fire, and the fire was blotted out! Where it had burned was a mantle of fresh and disordered snow.
The man was shocked. It was as though he had just heard his own sentence of death.
After this disaster the man begins to lose his self-confidence. The reader is held closely in the protagonist's point of view and feels the protagonist's growing panic as the situation becomes increasingly desperate. The man has to build another fire, but he is losing control of his fingers. Things go from bad to worse. Since he cannot use his fingers to light a single match, he takes the gamble of scooping all his wooden matches together.
Then he scratched the bunch along his leg. It flared into flame, seventy sulphur matches at once! There was no wind to blow them out. He kept his head to one side to escape the strangling fumes, and held the blazing bunch to the birch-bark. As he so held it, he became aware of sensation in his hand. His flesh was burning. He could smell it.
He is so clumsy with his frozen fingers that he puts his fire out while trying to remove a large piece of green moss which had been suffocating the feeble flames. He becomes increasingly desperate. He makes an unsuccessful attempt to kill his dog so that he can bury his frozen hands in the warm body and get some life back into his fingers. But although he manages to get his arms around the dog, he has no way of killing it, and the dog escapes. Then the man tries running, in the hope of restoring some circulation to his limbs. The running is helpful, but he can't run far enough. The camp he had been planning to reach before dark is too far away. He doesn't have the endurance. Several times he falls down and gets up again, driven on by the fear of death. Finally he gives up the struggle to survive and allows himself to drowse off. He finds that this form of death is not painful.
Then the man drowsed off into what seemed to him the most comfortable and satisfying sleep he had ever known.
The silent setting has seemed totally indifferent to the man's plight. The cold is killing him dispassionately. The spruce tree dumped its load of snow just because the branches were overladen. The man's dog stays with him for a short while after he is dead, but then it abandons his body and proceeds along the trail to the camp where it knows it can find other "food-providers" and "fire-providers."