The story begins with the unnamed man travelling on foot through the wilderness. He realizes it is actually far colder than 50 below but doesn't worry about it.
His only companion is a dog, the dog knows not to be out in this weather but the man cannot yet understand it, he is "without imagination." He tries to avoid danger by forcing the dog to go ahead of him.
He eats his lunch by a fire and feels confident about the journey despite the incredible cold. After lunch he falls through some ice and gets soaked but still doesn't worry too much.
After building a fire and getting ready to thaw and dry his wet clothes, the fire is smothered by snow falling from the try under which he built it.
Eventually he succumbs to the cold after trying to run to revive his frozen limbs and he realizes the "old timer" was right about the dangers of the Yukon.