The book I read is WoodSong by Gary paulson. Brian (the main character sets off on an amazing adventure in the I idtariod. The idtariod is 1,150 miles long it's a dog sled race in Alaska and it is 17 days long. From that lack of sleep he has hallucinations set in for example Brian turns his dogs to a glowing green tree stump. He walks up to it and all it is,is a tree stump glowing in the moon light. Another example would be the next day Brian gets tired and closes his eyes and opens them again and there is a big brown bear towering over him and he is very scared. By the morning he reaches to the finnish line. He stops and says should I go back to the Alaskan wilderness.