I just want to give a shout-out to everyone at Backyard Chickens. Somewhere on the site, I read about different ways to keep the water from freezing. During the winter we have the big plugged in water warmer set up but I had already put all that stuff away and didn't want to get it out again. I remembered that someone had written about using a light bulb or candle inside a cement block, and we had several of the half blocks available. So I got some cheap votive candles that said they burn for 8 to 12 hrs, put the cement block in the coop run (sand), made a little trench under the bock for air, put the candle inside the block hole on the sand (obviously the hole is upright), then I put small pieces of lath on the top of the block so there could be a place for air to exit, and put the metal water holder on top of that. It worked a charm, a simple way to let them have unfrozen water when they get up. They get up an hour or so before I get out there to open the run, and I didn't want to worry that they would not have water. During the day, it's not problem as the semi-free range fenced in area has a pond. So thanks to whoever wrote up their water solutions, it has been a quick and easy solution for those temporary freezing nights!