Debuff before killing the player

I want from the beginning. I don't know how to do this so I need help!

I want Player Like (1 or 2 HP) to be in a prone position
and it would have 5 minutes and if it passed the player would be killed by the command.
and I want it to be possible to save the player so that, for example, it can be picked up in 25 seconds.
But how?
I think that typing the command ( /Rescue )
to be counted, for example, on the exp bar
But the player would have to stay still. How To Help!