brown-bag it

when a person is hyperventilating/breathing too much air you brown-bag it, meaning the person has to breathe into a brown bag in order to lower its oxygen levels and calm down

Person 1: Oh man, I can't take this, this is just too much....*breathing heavily*
Person 2: Alright, you need to relax, calm down. We gotta brown-bag it *hands the other person the brown bag to breathe into*