Good question, and lots of good answers. I got my chickens last fall so this is the first summer for them (and me as a chicken owner in South Carolina). We've gotten up into the 80s the last two weeks and the birds have been very unhappy. Lots of panting and looking depressed. They were drinking out of nipple drinkers before, but I decided to put a pan of water (actually a small, clean cat's litterbox!) in their coop to see if they needed more water or wanted to stand in it. They loved it! They all drank a lot of water and promptly got diarrhea - but I read that's just another way for them to get rid of excess body heat... The chicken who seems to get the hottest - the most panting - stands in it too. I've also been spraying down the ground in their coop and they really like to walk in the puddles. They don't seem to want to be sprayed directly with the hose, but seem to be venturing close to it and running through it to get their feet and legs wet. It reminds me of kids running through a sprinkler! I've also got a jug of water in the freezer that I'm going to try putting out there when it gets really hot...