We did want to put a little heat source of some sort in our coop even though everyone says we don't need it. I don't know how much heat it actually puts out for them, but at least it made me feel better anyway knowing that they aren't totally w/o heat. I do need to hook up our base heater for the waterer tonight though.
Below is the link to what we bought.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200310679_200310679


http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200310679_200310679