According to the NBC website where you can meet the new warehouse guys, the blue muscle shirt that the bodybuilder from Oscar's gym is wearing says: "My balls have biceps and my biceps have balls."
Darryl's excuse for not having hired any new warehouse guys was "Four Hour Work Week." This is a reference to the book "The 4-Hour Workweek: Escape 9-5, Live Anywhere, and Join the New Rich" by Timothy Ferriss.
At the beginning of the episode, most of the staff show concern about a dog "trapped" in a car on a warm day. Oscar breaks a window to let air out. However, right before that, Dwight pours his drink into the open sun roof. None of them noticed that the open sun roof would release any build up heat.