Stood in the Fire is an achievement that is awarded for being killed by Deathwing at random in the world. The act of which time and zone he will spawn seems to be completely random, and is not affected by any zones or times he's spawned at previously. Thus, there is no way to determine ahead of time when a zone will be hit. It's not unheard of for some servers to see Deathwing scorch one zone countless times while other zones on the same server have yet to be touched.