One of the major characteristics of the man is his over-confidence, perhaps better described as hubris. London writes that "the trouble with him was that he was without imagination. He was quick and alert in the things of life, but only in the things, and not in the significances." He is repeatedly described as being adept at noticing things and understanding the very direct consequences but not the larger significance of those same things. Early in the story he seems to be confident in his ability to take such a journey in a cold snap because he'd been out in two cold snaps previously. He is unable to figure out that the fact that his spittle is crackling in the air means that it is far colder than anything he'd experienced before.
The man is also skilled in the technical sense. He knows that he has to avoid the springs and he knows how to quickly kindle a fire. But he isn't skilled enough to place the skills he has in context and understand that those skills are simply not enough for the bitter cold he has ventured out in. London writes "this man did not know cold" and compares him to the dog who knows the cold by instinct.