If Infinite Health doesn't work "ONLY" when you're entering an anti-Dragon area... don't go in one. It's more than likely dying in those areas is hard coded into the game and CANNOT be changed.
--------------------------------------------------------------------------- "Remember the good old days when you could just slap Omni-Gel on everything?" - Shepard, ME2
"Not right now. Trying to determine how Scale Itch got aboard. Sexually transmitted disease carried only by Varren..... Implications unpleasant." - Mordin, ME2