@sewhat , I am using frozen water bottles with water around them. I use three of them, and also sometimes scoop a few ice cubes from the ice maker and add that to the water so that it gets really cold really fast. But mostly frozen water bottles and they do seem to last a long time. Sorry to read that you are having trouble sleeping! I awakened this morning at 8:30 due to the neighbors mowing. Can't blame them for that, in this summer heat, but I usually prefer sleeping really late. So, I got up and moved to my recliner (farther from the windows and mower sounds), and napped for another hour before coffee. My knees are doing a little better this morning after all that icing yesterday.