Spas with thermal pool

A luxury day-pass wellness circuit inside Carillon Miami Wellness Resort, with sauna, steam, cold plunge and thermal pools in North Beach.

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.

Membership-style wellness studio in Strongsville with sauna, steam room and thermal pool, plus a $49 unlimited day pass for first-time visitors.

Hotel spa inside Florence's Four Seasons, with a walled garden pool, whirlpool, sauna, steam room and couples suite, open to day-pass guests.

A Korean jjimjilbang in Houston with clothing-optional bathing pools, sauna and steam rooms, $58 day pass, adults 18+ only, walk-ins welcome.

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

Adults-only spa inside the all-inclusive Ocean Riviera Paradise resort in Playa del Carmen, with sauna, Turkish bath and four treatment options via day pass.

Sante Spa is the adults-only resort spa at the Riviera Palm Springs, with 18 treatment rooms, a Watsu pool, steam room and validated valet parking.

Hotel spa at the Inn at Eagle Mountain in Fountain Hills with sauna, steam room, pools and a $69 60-minute massage as its signature treatment.

Adults-only hotel spa at El Conquistador Tucson with a salt therapy lounge, heated outdoor pool and mountain views, day passes available to hotel guests.

A five-star resort in the Tuscan countryside built around a natural thermal spring, with day passes from €39 for outdoor thermal pools, hydromassage circuits

A 38,000-square-foot resort spa at JW Marriott Desert Springs in Palm Desert offers day passes, saunas, a saltwater lap pool and couples suites.

Adults-only hotel spa in downtown Napa with thermal circuits, sauna, steam and cold plunge, plus massages, facials and medical aesthetics.

Adults-only resort spa in Sedona with outdoor hot tubs, steam rooms and a 30-treatment menu, open daily with walk-ins and day passes.

Adults-only hotel spa at W Scottsdale with thermal circuits, sauna, steam, cold plunge and a robotic Aescape massage option.

A resort day spa at Westward Look in Tucson with a thermal pool, sauna, steam room and cold plunge, open daily 9am-6pm by reservation.

Downtown Palm Springs day spa built around a natural hot mineral spring, with private mineral baths, sauna, steam room and massage.

A moderate-priced day spa in Charlotte's SouthPark area with a sauna, steam room and thermal pool alongside massage, facial and body-treatment menus.

Full-service resort spa at the Hyatt Regency Hill Country in San Antonio, with thermal circuits, cold plunge and day passes open to non-guests.

A hotel spa in downtown Miami with a day pass covering sauna, steam, cold plunge and thermal pools, plus 13 treatments on the menu.

Hotel spa deck in downtown Miami with sauna, steam room, cold plunge and thermal pools overlooking Biscayne Bay, day passes from $50.

Adults-only resort spa in Napa Valley with pools, sauna, steam and a fitness center, open to hotel guests and club members via day pass.

Adults-only hotel wellness setup in downtown Phoenix with a heated pool, sauna and steam room, day passes available for $50.

A 25-room Sonoma hotel in Forestville with a spa barn offering sauna, steam and pools, mainly for overnight guests.