[It's likely nothing, but Hange isn't one to dismiss concerns outright. So they offer some assurance:]

I'll check in on him, alright? After all, I know him better than anyone. I can read Levi's moods rather well.

[So if he's just stressed at everything going on in his living room or if he's sick, Hange will hopefully get to the end of it.]

[The burner is turned off, now it is time to simply let the suspension cool for a minute or two before they divide it up into proper doses. Sounds like a perfect time to finish that tea!]

Thank you for bringing this over, by the way. He brewed the nice batch!