Hello eden.
First, to address your issue.
There is not really anything you can do.
A burn (of this degree) should not greatly affect it. You might find that the tenticals will stop growing, but even if this does occour, it shouldn't greatly affect it.
Just keep an eye on it, that it keeps eating.
Perhaps hand feed it some fresh/frozen food (Forumal 1 or 2, if you have that over there).
And, if you'd like to take an extra step, get a sphion and go buy some plankton (pet store should have this... if they are any good) and direct-feed it.
Lastly, as Deleatidium suggested, go buy yourself a heater-cover ('heater condom', as I call them). Well worth the money, if you are going to do a invert tank. Another option, would be to invest in a submergable heater (if that isn't what you have already) and lay it horizontally (lengthwise) about 10 inches above the floor of your take, and about 10-12 inches from a major underwater jet/pump. And, if you have the extra coral, you can always surround the heater (with the condom) to prevent further tank-mate damage.
It may sound like an extreme, but if you are serious about your marine tank, and like most serious marine people are, you're going to have a few thousand dollars invested in a nice marine take... a simple 45-50NZD's to get yourself a heater-condom is a drop in the tank. (pun intended)
Anyway, just keep an eye on your new friend... make sure the other fish do not start attacking it's damaged tenticals (which they will be able to do, as a burn typically damages their barbs)... if this happens, isolate the poor thing until it heals over.
Later, and good luck!