The dog has true instincts: "The animal knew that it was no time for traveling. Its instict told a truer tale than was told to the man by the man's judgment." And when ice forms on its coat, "(i)t made quick efforts to lick the ice off its legs, then dropped down in the snow and beganto bit out the ice that had formed between its toes. This was a matter of instinct. It did not knowthis. It merely obeyed the mysterious prompting that arose from the deep crypts of its being."
The man chooses to ignore both his own insticts & the sound knowledge of others who have gone before him. As the man becomes increasingly freezing, "(he) remembered the advice of the old-timer on Sulpher Creek. The old-timer had been very serious in laying down the law that no man must travel alone in the Klondike after fifty below. Whell, here he was: he had had the accident; he eas alone; and he had saved himself. Those old-timers were rather womanish...Any man who was a man could travel alone."
Of course, he makes a fatal, hubristic error. He ignores the advice of experience, the instincts of his dog, and his own instinct in favor of being a "real man"...a real, dead man.
I don't think the situation is ever very unclear, except perhaps for the few times the man thinks he's "beaten" the cold a very weak flame of hope flickers.