“This was just what if someone could stop air. Nobody can actually do it. But did you mean in general?

“Yes, there are ways that you can hurt yourself. But there are more ways you can hurt yourself if you don't have control! You could stumble and hurt your unreinforced ankles and be unable to travel out in the wild like this!”

(Pause. Deep breath. Stop complaining about the entirely unreasonable situation (he has been not-thinking about what is going on here, because the evidence is accumulating in the wrong way, and even that doesn't make sense, not really) to the person in that situation. Don't scare the kid.)

He sits down on the rock.

“Sorry. I'm just worried a— for you.”