PS, this is a reference to some of Marisa's teased dialog which is:
だんだよ暑いじゃねーか このヤロー
I would translate that as:
What the hell, isn't it kinda hot? Asshole. Son of a bitch!
I don't know who this is directed at, but it's kinda funny if you think of it as being directed at ZUN for putting her in a scarf and mittens in the middle of summer.