This is a pretty chill, down-to-earth moment, but we can have those, right? Right?!
Look, if this is too mundane to you, just focus on how ridiculous Catalina's hair is for a bit, alright? Just stare at it for a bit and remember that everything is still ridiculous.
As for what they're talking about, I've been explained the SCIENCE! before, but ultimately all my memory seems to care about is "dehydration is a thing that can happen, drink some water".