Spas with upscale

Nashville, Tennessee

A Midtown Nashville wellness studio built around cryotherapy, infrared sauna, red light therapy, IV drips and recovery treatments, run mostly through monthly

Nashville, Tennessee

Day spa and medical spa on the third floor of The Westin Nashville downtown, with nine treatment rooms, a dry cedar sauna, steam showers and walk-in access to

Jackson Hole, Wyoming

A Jackson Hole facility pairing physical therapy, acupuncture and massage with a climbing wall, salt room, infrared sauna and sound healing, open to day-pass

Dallas, Texas

MD-owned medical spa in Dallas offering 46 treatments from HydraFacials to laser hair removal and peptide therapy, walk-ins welcome.

Sonoma, California

A boutique day spa in downtown Sonoma centered on infrared sauna and cold plunge drop-ins, plus massage, red light and PEMF therapy.

Auckland

Hotel day spa at Pullman Auckland CBD with a 25m heated pool, sauna, steam room, jacuzzi and gym plus massage and facial treatments.

Austin, Texas

Adults-only hotel spa at the Fairmont Austin with nine treatment rooms, a hydrotherapy circuit, sauna and cold plunge, open daily with day passes available.

Palm Springs, California

Hotel spa at the Renaissance Esmeralda in Indian Wells offering desert-inspired treatments, a recovery lounge, steam rooms and day passes, adults only.

Piešťany, Trnava Region

Spa Irma on Piešťany's spa island offers historic mud and mirror thermal pools, a hydrotherapy circuit and a 60-treatment medical spa menu, adults only.

San Diego, California

Adults-only hotel spa at Kona Kai Resort on Shelter Island with six treatment rooms, a couples' suite and day-pass access for non-guests.

London, England

A Russian-style banya bathhouse in Belgravia offering oak-lined steam rooms, cold plunge pools and leaf-massage rituals, with day passes by reservation only.

Orlando, Florida

Adults-only hotel spa at Disney's Grand Floridian Resort with massage, salon services and a fitness center, open to walk-ins daily 9am-6pm.

Charleston, South Carolina

A King Street medical spa in Charleston's Harleston Village offering injectables, laser and skin treatments through nurse-practitioner-led membership plans.

Santa Ynez, California

Adults-only resort spa inside Chumash Casino Resort in Santa Ynez with 21 treatments, a mineral pool, cold plunge and couple's suites.

Napa Valley, California

Adults-only hotel spa in Napa Valley with a co-ed thermal circuit of sauna, steam room and cold shower, open daily 10am–6pm; day passes available.

Hunter Valley, New South Wales

Large day spa at Chateau Elan in Hunter Valley with 17 treatment rooms, a float tank, outdoor mineral spas and couples' treatments; day passes and walk-ins

Las Vegas, Nevada

An adults-only hotel spa inside Encore Las Vegas with whirlpool, sauna and steam room, open daily for treatments and day passes, walk-ins welcome.

San Diego, California

Adults-only hotel spa in Carmel Valley with a hydrotherapy circuit, two fireplace lounges, and a $100 day pass covering pools and fitness facilities.

Chicago, Illinois

Adults-only hotel spa inside JW Marriott Chicago offering massages, facials, nail services, an indoor pool and steam room, open 8am-8pm daily by appointment.

Killarney, Munster

A hotel spa in Killarney National Park with an adults-only Vitality Suite of hydrotherapy pool, sauna, steam room and outdoor hot tub.

Napa Valley, California

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

San Diego, California

Adults-only day and hotel spa in Rancho Bernardo with gardens, whirlpools, a steam room and an 18-treatment menu, open daily 9am-6pm.

Calistoga, California

A 20,000-square-foot resort spa in Calistoga with five geothermal pools, Calistoga mud treatments, and a day pass for non-hotel guests.

Asheville, North Carolina

Adults-only hotel spa in Asheville with a fiber-optic-starred lap pool, waterfall pools, saunas and an electronics-free policy; day passes are limited and