How hot are we?

I got back from class today about 7:30 and my apartment was sweltering!  I live on top of a pizza parlour with great big, single pane, sounth facing windows.  Between the sun and the pizzza oven under my bedroom the apartment gets toasty.  I can't wait till winter when I'll appreciate the warmth.  Until then, we keep all the windows open hoping the breeze will pick up again for just a few minutes...