Cheat death

Hey! Im working on a Minecraft experience, where you quite often come close to death. However for story purposes of the video later filmed with this map, I need to keep the players alive...
Basically, is there a way to make the player be able to get to 1 hp, but not below? (the player shouldn't be aware of the fact that they are invincible) 😅 
Hopefully this inst too confusing, thanks for your time 🙂