Brain gets no more blood. Neural biochemistry breaks down. Brain dies. You die. That’s it. Except for some incoherent and contradictory texts from bronze-age books or wishful thinking by naive people, there is ZERO scientific evidence that heaven or reincarnation exist. Even Buddha never suggested we would reincarnate, that was an idea added later by some of his followers. The bible is very flimsy on the entire concept of hell and heaven.