My chickens were sneezing with runny noses. I have them on Duramycin from TSC just in case. It has been 5 days now and they seem to be doing better. In my area of Michigan the weather has been anywhere from sunny and 60 degrees to rainy and 45 degrees or 35 degrees and snowing. Miss_Jayne told me to be sure that I have all the coop windows open (even though they free range during day). Basically, you don't want it to get damp in there. Hope this helps.