One lesson from "how to build a fire" is to use your imagination at all times so you think about how cold it is or how cold you are. Especially when you are in the yukon and you think it is about 50 below 0 but it is actually around 75 below 0. A detail from the text that supports this is ''Fifty degrees below 0 meant eighty degrees of frost. Such fact impressed him as being cold and uncomfortable..."This shows he should have an imagination he would have a better chance of making a fire which would lead to living. Another lesson from how to build a fire is to listen to other people even if you don't think they would now. A detail that supports this is "perhaps the old timer in Sulphur creek was right. If he would have had a trail mate he would not have been in no danger." This shows he should have listened.