In Jack London's "To Build a Fire," the dog, as part of nature, is set in contrast to the man.  Still more wild dog than domesticated, the husky is equipped for bitter cold.  His thick undercoat insulates him while the long oily overcoat repels both the cold and the snow.  His feet are flatter on the ground than other dogs--as though he has mini-snowshoes on--and he instinctively knows to bite the ice from his feet when he steps through the ice.  Having done so, the wetness does not permeate his fur and he is yet warm.

On the other hand, the man, having become wet, must try to build a fire in order to dry his feet.  To do this, he must expose himself, especially his fingers to the cold for a brief, dangerous time.  As he "threshed with his arms and hands, [the man] felt a great surge of envy as he regarded the creature that was warm and secure in its natural covering." And, so, "there was no keen intimacy between the dog and the man."  For, the dog

was not concerned in the welfare of the man; it was for its own sake that it yearned back toward the fire.

while the man, who "lacks imagination," is not in touch with nature; he is "ignorant of the cold." He realizes too late that the man from Sulfur Creek has spoken the truth; he realizes too late that "one must not be too sure of things."  One cannot outwit nature.  This the dog knows. 

As the man is a "cheechako" or newcomer to the rigors of the Yukon, he is setting himself up for failure by not following the advice of the old-timers. He is over-confident in his own abilities and ignores the "womanish" advice not to travel alone in temperatures below -50 degrees. In addition, London tells us in the narration that the man is "without imagination", a dangerous failing in the harsh, frozen north. As he falls victim to hypothermia, his reasoning begins to fail. His decisions become without logic. He is ill-prepared going without extra food and matches in case of an emergency. He is arrogant in not observing the dog's behavior and learning from it. He pays the ultimate price and dies from his own ignorance and over-confidence.