After knocking out an enemy, will the enemy eventually wake up?

In Burial at Sea - Episode 2, after knocking out an enemy for the first time, Elizabeth comments that he's not gonna get up anytime soon.

But since the enemy isn't dead, does that mean he'll eventually wake up? If so, how long does he remain out of commission? Should I leave an area promptly after dispatching enemies non-lethally? I'm playing the game in 1998 mode, so I won't be allowed to kill anyone.

Turns out the bodies of knocked-out enemies disappear after a short while like the bodies of enemies that are dead — even though knocked-out isn't really the same thing as dead. Either way, maybe Elizabeth was right.

That said, it's best to keep going anyway. There are far more pressing issues to be taken care of, like

rescuing Sally.