In Jack London's story "To Build a Fire," the setting does function as a kind of character in the story. The weather is too cold to be out as he could truly freeze in these temperatures. He chooses to travel by the river bed which is too dangerous because he could get wet which is a true disaster at this level of cold. So, yes, the weather does function as a foil for the man and his disregard for the advice of experienced old-timers who did warn him about traveling alone in this kind of cold. However, I see the true antagonist in the story as the man's lack of imagination and his unwillingness to listen to the voices of experience. He simply cannot imagine that his own powers of reasoning are not enough in this wilderness. He doesn't watch the dog's reluctance and subsequent bout with the water with any kind of thought that this might be a warning to him. When the first fire is extinguished, even then he isn't frightened enough. It is only when the second fire is put out by the snow that he truly understands that he will now face death through his own arrogance and reluctance to listen to anyone else's advice. At the end, he even acknowledges the correctness of the old man's advice, "You were right, old hoss; you were right."
thkx so much for ur help Mizzwillie