when using a hireling with a warrior skill how do they take the brunt of it?

The players I’m GMing are looking to get a hireling who’s a warrior. Looking at the description it states

If your attack results in consequences (like a counter attack) the man-at-arms takes the brunt of it.

It also states that a hirelings HP isn’t important. How do I damage him, figure out if he’s dead, if I don’t know his HP?

also looking at burglar it states:

Most traps leave a burglar in need of immediate healing.

how can I heal him if I don’t know his HP?