Answer: The cold setting of the Arctic terrifies Sam McGee, so he asks the speaker to cremate him so that his remains do not freeze.
Step-by-step explanation:
Sam tells the speaker that he feels like he´s going to die from the terrible cold of the Arctic. He even claims to be more afraid of the cold than of death itself. His biggest fear is being buried in a freezing grave, so he asked the speaker to promise to cremate his body when he dies, so his remains don´t end up freezing in the cold.