You know, I'm surprised nobody's mentioned it yet, but pools can also cause *severe* sickness. I've survived dooming, stat loss, intrinsic loss, even elementals, but I have lost at least a dozen characters to pool sickness. It dealt something like 30-40 damage, and I never got a turn to use herbs. That's an insta-kill for most characters less than level 6 (more, if you like mist elves). That's why I usually limit my poolsipping until I'm about ready for the Pyramid. I usually don't have intrinsics anyway, and I can usually run to Dwarftown by then.