I can't remember the exact words of the area name, but the "Magma Fissures" exploration areas have damage ticks that can go up to 6 times per round in them, often though only having three.
Still though it's impossible to outheal this damage or even run away from them, might be worth having a look at it.
Maybe fixed?
If it happens again please present screenshot of the area in question..
Made the ticks less frequent.