I tried to quest in Hellfire.  Yep.  I watched a 90 orc warrior smash a mage in front of my face.  Then as I waited to die, he waved.  A 90 mage and ele shaman fell from the sky and blasted me into the canyon.  I disengaged to survive the landing, only to be smoked by a 90 rogue.  Good times.

On the plus side when they are my level, or even a little higher, I always kill them.