I read on BYC about using frozen jugs of water to keep the girls cool. I set a half gallon milk jug on its side under the coop, where my 2 hens hang out most of the day. We set it out in the a.m. and it's melted by the time we get home to let them out to free-range. Then...I got an idea about a frozen auto waterer. Here's the prototype. Half gallon frozen milk jug held in place with some bungees (If it works ok I'll make a more user friendly version), got it dripping into a old Christmas cookie pan. BTW...they still have their little 1 qt. waterer as a backup for now. We hit 104 the other day here in north MS.