How is the dog wiser than the man in "To Build a Fire"?

London uses this story to criticize the arrogance of man.  Though man has been gifted with the ability to reason, this gift often works against man by allowing him to ignore his instincts.  In this book, the man has "reasoned" that he is intelligent enough to protect himself from the elements as he travels across the Yukon Territory.

However, the dog is relying on his instincts.  The dog knows that it is too cold to be out.  He knows to bite away the ice from his fur after being in the water, though the man does not know to keep his glove on.  The dog is reluctant to leave the fire, but the man assumes he'll be fine after the brief warm-up.

The dog knows to shrink away from the  man when the man has decided to burn the dog.  His instincts warn him of the danger; instincts the man has been ignoring in himself.  Finally, the dog knows that he can survive by curling up and using his own body heat, while the man makes himself worse by fighting with the fire.