Yes and yes.
Heaven and Hell are 'places'. Whether or not they really exist is debatable and yet to be proven (I don't believe either place exists and am not of any denomination of Christianity), but they would still be capitalized as they are proper nouns. Make-believe places in story books are also capitalized, although they do no exist.

That said, while I know this, I actually tend not to capitalize them most of the time. I wasn't raised Christian and I never have been Christian, and it feels strange to me to capitalize them. Like I'm giving them some sort of validation in my own life. If anything, I seem them as general ideas, a concept, an idea, a metaphor. It's never come naturally to me to capitalize them and I would have to think three times before doing so. I realize this can be seen as quite disrespectful. I guess I just don't use the words often enough to worry about it much.