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.

A beachfront resort spa in North Beach, Miami with cryotherapy, a floating salt bath, sauna, steam and a cold plunge, open to walk-ins and day-pass guests.

Adults-only spa and pool complex inside Loews Miami Beach Hotel, open to hotel guests only, with sauna, steam, cold plunge and thermal circuits.

Adults-only resort spa in Fountain Hills with sauna, steam room and outdoor pools, offering day passes and an amethyst facial as its signature treatment.

Adults-only hotel spa inside La Concha Resort in Condado, San Juan, offering couples massages and a small treatment menu for guests 18 and up.

An adults-only hotel spa in Old Town Scottsdale with sauna, steam room, cold plunge and thermal pools, open to hotel guests 21 and up.

A hotel spa at Eden Roc Miami Beach in Mid-Beach with sauna, steam room, cold plunge and thermal circuits, open to resort guests only.