Help! F-R-E-E-Z-I-N-G weather coming some chicks have swollen eyes and they are shut. They are in a covered coop, with heat lamps and a plastic tarp covering open areas. They have fresh air.. Some have just died! Most are 3 months old but all are feathered. I cant put in the barn I have smaller chicks. What can I do... BBBRERRRRRRRRRR ??? temps of 18-23 degrees are expected in Texas. Please advise Help Emergency!!!!!