What is the moral lesson in the story "To Build a Fire" by Jack London?

The moral lesson in Jack London's short story "To Build a Fire" is that people should not think they are more powerful than nature. In addition, people should listen to others who have more experience than they do. London writes of the protagonist of the story, "The trouble with him was that he was not able to imagine." Though the man is new to the Yukon Territory, he ventures out on a sunless day while thinking that he can survive the cold. Though it is fifty degrees below zero, he has no real conception of what that means to him, his body, and his safety. As London writes, "It did not lead him to consider his weaknesses as a creature affected by temperature. Nor did he think about man’s general weakness, able to live only within narrow limits of heat and cold." The man is limited by his previous experience, so he thinks, without any evidence or reason, that he can outwit the cold, though people have warned him that he can't. In reality, the temperature is even colder than 50 below zero, and as the man dies, he thinks, “You were right, old fellow. You were right" about the old man in Sulphur Creek who had warned him not to venture out. In the end, the man realizes that nature is more powerful than he is and that he should've listened to people with more experience in the region.