I think the current version is fine.
To justify the gain in health, as a fire spreads, it gets harder to put out.
This card is not OP (not by a long shot), but there are enough situations in which it would be useful, that it is not UP.
Furthermore, I am still hoping that there will one day be a card that generates a gem (like a nymph's tears, but for gems), and thus, I am also considering its possible place in a deck that revolves around that, and, I still think it is balanced under those circumstances.