What to Wear?

Today I'm going shopping for some recovery clothes.  Everyone keeps telling me to wear comfy lounge clothes that zip or button up; problem is that all of my clothes that zip or button are long sleeved, and it's June, and we have no central AC.  I was thinking about buying some loose tube-dresses or swimsuit coverups.  It's difficult to imagine what I'll need or how much I'll be able to move my arms.  Hopefully I'll be able to find something!