I used one of these when we go to football games sitting o ice cold metal bleachers. It really worked and thought maybe it might help in the nesting boxes. It was 23 degrees this morning and I had a couple frozen eggs from my "drop em and leave em" hens. Here is a link to it. It's called, heat a seat. http://www.gandermountain.com/modpe...&kpid=444843&gclid=CJ7Jh5HX2cECFc87MgodjiUAMg