This is how you make a hot tub, hillbilly style. Three guys from the prairies of Illinois turned an old stock tank sitting in the open air into a jacuzzi, and heated it up using quicklime, that scary caustic stuff that burns your skin off if you're not too careful. A video of how they did it, using gas masks, tin baths and a lot of ingenuity, is after the jump.
Rather like a reverse-Bain Marie, the guys floated three metal tubs, each containing fifty pounds of quicklime, in the "jacuzzi." When water was added to each container, the quicklime fizzed away, heating the 700 or so gallons of water to the perfect temperature, 100ºF. You've got to love the palm-tree background, set off by the Hawaiian shirt sported by one of the tubbers. [PopSci]