Originally Posted by johnvk7

I would say so, at least head gaskets/ head repairs.

Initially, it may have been an air lock in the cooling system from not being bled properly.
But if you kept driving with the needle in the red, you have most likely damaged the engine.
It doesn't matter how hot the ambient temperature is, the needle should never go above half on a Subaru.
Call your mechanic, tell him/her whats happened.
If he is at fault, he will have to fix it at his expense. But only if its his fault.