Question: Can you bring people back to life, or preserve them?

Sam Geen answered on 24 Jun 2013:

You can bring people back from near death, if their heart has stopped but their brain is still OK. Some people think it might be possible to revive people hours after they’ve technically died. But once the brain starts decaying, it’s impossible to bring someone back.

Preserving people to revive them later is difficult – sometimes if you keep people very cold they can be brought back to life (for example, some people have fallen under icy lakes and been revived). But the problem is that if you freeze someone, their cells can explode from the ice expanding. So it’s not easy to do, and no-one’s managed it properly. But some people do get cryogenically frozen in the hope that people in the future will be able to bring them back to life.