My 4th grade teacher read a chapter to the class every day, same with the sequel. I specifically remember the part where he was standing outside naked in winter and some tree bark just kinda exploded, and he was freaking out trying to decide if the freezing bark caused it to expand and explode or if a hunter was out there shooting bullets at him. Also, the part where he finds an orange-drink packet in the survival supplies of the plane and describes the taste of it.

Edit: I think the tree bark part was in the sequel, Brian's Winter.