Everyone does his or her share, even the animals. Talk about the draft horses. Do some research on the different breeds and their particular strengths. The cold plays a part in this story. He talks about the blue of cold.
Frostbite is dealt with.
At one point the boy is freezing to death. Talk to an eye doctor about it. A distinction is made in the book between killing and hunting animals. Contact animal rights organizations and furriers to get their sides of the debate. There are some pretty graphic descriptions in the book of preparing killed animals for food.