A really small detail from my work-in-progress. I have a character ripping apart his wool cloak to use part of it to make a torch. He does this by setting it on fire in lava. It's a desperate act and doesn't need to produce an effective torch, but I started wondering: what would happen to the wool?

This is a fantasy story set in an ancient sort of world, so the wool would be untreated, and in this case, the cloak is finely made for an upper class gentleman, i.e. light weight. Am I off the mark in thinking that such a garment could ignite for a little bit? How quickly do you think it would smolder out?