Maybe it's being obsessive, but I decided to install a very old roller shade to ward off some heat in the 90 degree plus attic. I struggled to figure out how to install the clips on the end of the shades, but managed anyway. I'm not sure the heat will be reduced, but maybe I got some sense of control over an impossible situation. It's also easier to air out by pulling on the shade, rather than fidgeting with an old cloth I'd hung from window corner to corner twice a day.