What is the conflict between the man vs nature in "To Build a Fire"?

The conflict is that the man is traveling in well below
zero temperatures, and he is all alone, except for his dog. The dog knows it is too cold
to be out in this cold weather. The old timer at Sulpher Creek warned him not to travel
alone.

Anytime your spittle crackles and freezes before it
hits the ground, it is too cold to be out. Nonetheless, the man is trying to make it to
camp where the boys are by six pm.

Possibly, the man might
have made it if he had not stepped in water up to his knees. The ice looked solid but a
flow of water bubbled just below the surface, and the man is now soaked up to the
knees.

In one way, this is the deciding factor as to
whether or not the man lives or dies. The man's fingers are frozen and he cannot get a
match to light. There will be no fire. The man's inner conflict is fading. Nature is
winning. When the man can fight no more, nature takes his life and the man
dies.