Write a brief analysis how "To Build a Fire" employs a direct observation of setting and precise concrete details to elicit an emotional reaction from the reader and present qualities of nature that connect to the school of naturalism

Naturalism in literature is a broad and deep topic that entire courses can be built around. In simpler terms, naturalism in literature is a genre that emphasizes observation and science over fiction. The stories themselves might be fiction; however, there is a strong emphasis on staying as realistic as possible. In this regard, naturalism relates to realism, but naturalism has a few additions of its own. Naturalism tends to be very deterministic: a character's fate is unavoidable and outside of his or her control. This paints nature as cold and indifferent toward mankind.
This view of nature can be seen in London's short story "To Build a Fire." One very concrete way that readers are shown nature's uncaring attitude about humans is the fact that the protagonist is never named. He is simply a man in the frozen wasteland. Who he is doesn't matter. As for concrete, nature details, readers are told that the sun hasn't been seen in days. We are told that it is cold enough to freeze spit, and any sort of land is hidden beneath three feet of ice and at least as many feet of snow. All of these details are important details that help to raise suspense. Most readers know that the man is in an incredibly dangerous environment; however, the man has a numb and uncaring attitude about all of it. He seems to be as indifferent to nature as nature is to him.

But it did not matter much, he decided. What was a little frost? A bit painful, that was all. It was never serious.

Unfortunately for the man, the frost and the cold is quite serious. His indifference to nature's harsh realities ultimately leads to his demise, and nature doesn't care one bit.

Then it turned and ran along the trail toward the camp it knew, where there were the other food providers and fire providers.