As it is with the case of almost all classic literature, the short story "To Build a Fire" has many themes or messages. One of the most obvious would have to do with the arrogance of humanity in their thoughts of superiority.
London sets the main character up as a tragic one. He is a "chechaquo" and is warned by the old timer, who he thought of as "womanish", to not go alone. He listens to no one and ignores the danger signs of nature as he continues his journey. It is noted on several occasions that the dog that accompanies him "knows better". It would not be out in this extreme cold if it were not for the man. In the end, his survival depends on his ability "To Build a Fire" and he fails, while the dog survives. The dog is a part of nature and does not need such things for survival. This story points out the weakness and frailty of humans in the world.