Why can't the man eat his lunch?

From the text:

"Then he sat down on a snow-covered log to eat. The sting that followed upon the striking of his fingers against his leg ceased so quickly that he was startled. He had had no chance to take a bit of biscuit. He struck the fingers repeatedly and returned them to the mitten, baring the other hand for the purpose of eating. He tried to take a mouthful, but the ice muzzle prevented. He had forgotten to build a fire and thaw out. He chuckled at his foolishness, and as he chuckled he noted that the stinging which had first come to his toes when he sat down was already passing away. He wondered whether the toes were warm or numb. He moved them inside the moccasins and decided that they were numb."

His hands were numb, his mouth was frozen (he's been spitting and drooling chewing tobacco, which has frozen the area around his mouth). He needed to thaw them all out before he was able to eat his lunch.

What is the man’s basic approach to life? from " to build a fire"