Why does the man in to build a fire build an emergency fire?

In Jack London's "To Build a Fire," the man builds an emergency fire to stave off the extreme cold and prevent hypothermia as he realizes he is in a life-threatening situation. After getting his feet wet and facing the bitter temperatures of the Yukon, he understands that maintaining warmth is crucial for survival. The fire symbolizes his struggle against nature and his desperate attempt to save himself from the impending danger. Ultimately, his failure to successfully build and maintain the fire reflects his underestimation of the wilderness and his own limitations.