Makers of the York tub say it will keep bath water warmer in even the coldest of winters. It’s made from materials with high insulation properties — finely ground volcanic limestone mixed with high-performance resin — that, in combination, work like the walls of a Thermos to prevent heat loss. That’s different from cast iron — which must first absorb the heat before it can retain it — and acrylic, which lacks any practical insulation value. Cost is $2,900.
Victoria + Albert, 800/421-7189, vandabaths.com.