Survival depends on companionship.

Through the man’s preventable death, “To Build a Fire” demonstrates that people need others to survive. The man rejects potential companionship in a number of ways, thus leading to his death. First of all, he is traveling on his own, accompanied by only a dog with whom he has no real bond. He also rejects an additional form of companionship: advice from others. He had been warned by the “old man on Sulphur Creek” about the extreme cold but ignores the warning and even questions the old man’s masculinity. He assumes that he can rely on himself and his own knowledge, rather than others’ knowledge and experience. The old man also warned him not to travel alone, but again the man ignores this advice. Even after he falls in the water, he thinks scornfully of the old man and his advice, thinking to himself that “old men were rather womanish… Any man who was a man could travel alone.” He soon learns he is wrong, however, when snow falls on his fire and puts it out. He realizes that if he had a companion on the trail, said companion could build another fire when the man becomes unable to do so. The man rejects even the non-human companionship the dog could have offered him. Instead of caring for the dog, he treats it cruelly. Their relationship is transactional, and so “the dog was not concerned with the well-being of the man.” In the end, the man realizes that his own pride has killed him. His last words indicate that he understands now how survival depends on companionship, as he says of the old man from Sulphur Creek, “You were right, old fellow.”

People are subject to the laws of nature.

The deadly events that befall the main character suggest that people are subject to the laws of nature, even though the man believes human beings have overcome them. He thinks that it is 50 degrees below zero, and that this degree of cold can be guarded against by human clothing: “mittens, ear coverings, warm moccasins, and thick socks.” He thinks this will be enough to protect him and does not spare much thought for “man’s general weakness, able to live only within narrow limits of heat and cold.” Although he notices the cold, he believes that the temperature will not really affect him since he has the human capacity to build a fire as protection. The first fire he builds works and “the cold [is] forced away.” However, the man’s ability to build a fire falters later on as his hands and feet grow too numb. Without fire, he is left exposed to the elements. His body begins to freeze, and his heart slows down. His human body does not have the endurance to run to camp where he can find warmth. Despite the power he thinks he possesses, he is still limited in what he can achieve, and the cold slowly kills him. In the last scene, the dog considers the man’s lack of power and overall common sense; it had never known “a man to sit in the snow like that and make no fire.” The man has believed himself to be superior to nature’s power, and dies as a result.

A small error can lead to catastrophic consequences.

The events that bring the man to his death show that a small error can lead to catastrophic consequences, especially in the precarious world of the Yukon. The man had been cautious, traveling carefully along the frozen creek bed, but he breaks through the ice and gets wet to the knees. This is an accident, by all accounts, since “there were no signs” of any water beneath the snow. But then the man makes an even deadlier mistake when he builds his fire under a snow-covered tree, and falling snow from its branches puts out the fire. The narrator has already explained how this can be deadly in extreme cold. However, the man is reluctant to accept this. He keeps trying to build another fire, but his first mistake builds into more. Because his hands are so cold and were not warmed by the first fire, they become numb and ungainly. He cannot strike a match: “The dead fingers could neither touch nor hold.” As he grows colder, his body shakes and scatters the fire he finally got going. The man tries to kill the dog to warm himself, but “his hands could not grasp.” He tries to run, but soon finds that he is losing feeling in his body. Eventually the frost “[moves] into his body from all sides” and he dies, all due to the chain of events that begins, ostensibly, from the unforced error of building his fire beneath a snow-covered tree, though it could be argued that his first error was traveling alone in the first place.