After four hours of a roaring wood fire, the temperature in our tub had warmed up to a balmy 11C. This isn’t quite the failure that it sounds like - after all, the water began at 5C, the air temperature was -5C and it was snowing. Somewhere in the heating process, Nate raided my shop for excess extruded foam insulation, hoping to hold more of the heat in the water. It didn’t work, but the pink insulation adds some nice color to the photos, I think.Link
Reader comment: Jamie McCarthy says: "A friend of mine was burned very badly on much of her upper body when the burn barrel in her friends' homebrew hot tub tipped onto her."
"Ethan Zuckerman's site is down now, so I don't know what kind of disclaimers he includes (except "horrible idea," which sounds about right). But in any case, please let your readers know: unless their idea of a good time includes lengthy hospital stays, months of physical therapy, and maybe death and stuff, they might want to skip the DIY hot tub."