Answer:
In to build a fire, the character who is facing the conflict in Jack London.
The The type of conflict he is facing is both, external and internal. This is because the external conflict in the story is the man's struggle with nature. The internal struggle is within the man himself.
The problem the character is struggling against is that He doesn't realize (or does in fact realize but does not pay attention to) the danger that he is facing.
He is unable to build a fire to stave off the cold and dies because of it.
They could have solved this problem by paying attention to the danger and the consquenses.
Hope this helps :) <3 :>