Here's my own perspective on it. It's merely that, not a claim of universal truth.
Heaven is life with God. Hell is life apart from God. He has given us that freedom of choice. Each of us can be with Him or separated from Him.
Jesus, on the Cross, cried out in agony not over the torturous bodily experience through which He was going but when He experienced hell: "My God, my God, why have You forsaken me?" That is a perplexing statement, unless one realizes that in order fully to experience the human condition it was necessary that God the Son be separated from God the Father. That is what death truly is. Resurrection is restoration to life as a child of God.
Heaven and hell, in that view, are wherever you are. You carry the one you choose around with you. I therefore have no argument with those here who say they are in your mind, for I believe that is indeed where either is to be found.