Last week the heat index was 110, now the forcast is mid 60's for the next few nights, when do I close the windows? Bob and the girls are 16 weeks old and I am new to chickens. At what tempature do I start to close up the coop. They have weathered the hot summer with a fan and all windows open but now I have to think about the tempature regulation. I plan to close the south window for mid 60's and start gradually closing them all. Any tips from the experts. I could use some advise.