THE modern wood-fired hot tub was developed in 1979. In the previous decade, regular hot tubs had become a wink-wink symbol of debauchery, but there was nothing lascivious about this woodsy new entry.

Using mostly recycled materials, a Welsh carpenter turned an old wagon into a relaxing refuge. ... Inside a converted ‘chalet on wheels’ truck with a spa-style hot tub By . Hannah Frishberg.