The states of being called “heaven” and “hell” begin here in this life, and are fully consummated in the age to come.
If we have allowed our hearts to be purified, then God’s presence will be healing, joyful, and life-giving. If we refuse God’s healing embrace, then His love will burn like fire, “for our God is a consuming fire” (Deut 4:24, 9:3, Isa 33:14, Heb 12:23)
More concisely:
“[St Gregory of Nyssa] teaches that Paradise and Hell do not exist from God’s point of view, but from man’s point of view. It is a subject of man’s choice and condition.” ~Metropolitan Hierotheos of Nafpaktos