I have always lived where it doesn't get cold enough for burmation and came up the ice chest method. It can be a pain because you have to check them daily but has worked well. I have bought large plastic ice packs from Target and if you use a couple it can keep the ice chest cool for 12 hours depending on the room temps. I change them once at night and once in the morning. As RoseBuds said, it can be a pain but I haven't found a better option.