Spas with upscale

Adults-only hot springs resort on Miracle Hill in Desert Hot Springs with private mineral tubs, a Finnish sauna, salt room and 35 spa treatments.

Adults-only hotel spa at The Scott in Scottsdale with six treatment rooms, sauna, steam and pools, plus day passes for non-guests.

Hotel spa on the lower level of the Fairmont Chicago, open to guests for massages, facials and a couples suite with an infinity-edge soaking tub.

Hotel spa and rooftop wellness deck in New Orleans' CBD with sauna, steam, cold plunge and thermal circuits, restricted to guests 21 and up.

The spa at this all-inclusive Puerto Morelos resort offers hydrotherapy, massages and facials for hotel guests only.