Water freezing solution - no electrical?

[Hokum Coco]

collecting eggs before they freeze swap out the black rubber bowls of water

You and I do the exact same thing. I surround my black water bowl with manure which will compost in a perfect world if it is NOT TO COLD. It will keep the water thawed in minus º (I live in Canada and am subject to -40º temperatures) and may only change the water once a day if I am lucky.