Teleport Minecraft to 1 heart?

br
2

I'm building an MC adventure map and if someone in my PvE area has only half a heart left, I want to teleport the person to another point (he should not die). Probably can with

/ execute if entity @a [nbt = {…}]

Be solved, but do not know what comes in there for an NBT value. Does anyone have any idea about it? Or a list with all existing NBT data? Or is there another possibility (it would be good with only one command block)? Would be very nice, thanks

Be

/ execute if entity @a [nbt = {Health: 1b}]

You can easily find this out using the following command

/ data get entity PLAYER

You must replace PLAYER with the player name

br

Thank you very much, that will definitely help