Spas with reservation required

Las Vegas, Nevada

A Summerlin day spa centered on Himalayan salt rooms, plus massage, facials and Reiki, open daily 10am-7pm.

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.

Scottsdale, Arizona

Resort spa at Camelback Inn in Scottsdale with 20 treatment rooms, a thermal circuit and day-pass access open to non-guests.

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.

Austin, Texas

A hotel spa in downtown Austin with six treatments, a salt-wall relaxation lounge, eucalyptus steam rooms and a fitness center, open daily by reservation.

Napa Valley, California

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

Miami, Florida

Hotel spa at The Ritz-Carlton Key Biscayne, Miami, with treatment suites, sauna, steam room and whirlpool, open to hotel guests 18 and up by appointment.

Miami, Florida

Hotel spa inside Trump National Doral with 42 treatments, couples massages, sauna, steam room, cold plunge and jacuzzi, open daily 9am-7pm.

Pittsburgh, Pennsylvania

A South Hills float center offering sensory-deprivation float tanks alongside sauna and cold plunge, with a 60-minute float starting at $89.

Washington, D.C., District of Columbia

A float therapy studio in Alexandria offering sensory-deprivation floats, sauna, cold plunge, and red light therapy sessions.

Cedar Park, Texas

Cedar Park float spa offering sensory-deprivation float therapy plus sauna, steam room and cold plunge, open daily 8am-10pm.

Austin, Texas

Float tank spa in South Austin's South Lamar area offering sensory-deprivation floats, sauna and cold plunge, with walk-ins welcome.

Miami, Florida

Hotel spa at The Setai in Miami Beach with 7 ocean-view treatment rooms, 5 couples suites, saunas, steam and a cold plunge.

Austin, Texas

Hotel spa inside Austin Proper with 15 treatments, a cold plunge and sauna recovery room, open daily by reservation.

Palo Alto, California

A Palo Alto day spa built around private hot tub and cold plunge suites, with about 50 treatments and couples options, open daily by reservation.

Scottsdale, Arizona

Adults-only hotel spa at the Fairmont Scottsdale Princess with a rooftop pool, grotto waterfall pool, sauna, steam room and cold plunge, open daily 6am-7pm.

Houston, Texas

A Houston day spa on E Airtex Dr with two locations, offering massage, facials and body treatments alongside a sauna, steam room, cold plunge and thermal pool.

Houston, Texas

Luxury day spa near Houston's Galleria with massage, facial and body treatments, a salt room and infrared sauna; reservations only, no walk-ins.

The Colony, Texas

A day-soaking spa in The Colony with mineral pools at varying temperatures, seven saunas, cold plunges and a poolside café.

Park City, Utah

A reservation-only day spa in Sandy, Utah, built around scalp spa treatments, plus sauna, steam, cold plunge and thermal pools.

Seattle, Washington

A moderate-priced day spa in Bellevue's Wilburton area offering full-body massage and foot reflexology alongside a sauna, steam room and cold plunge.

Minneapolis, Minnesota

A St. Paul wellness studio in Macalester-Groveland offering infrared sauna, float tanks, salt therapy and cold plunge by reservation, adults-only, day-pass

Colorado Springs, Colorado

A moderate-priced holistic wellness center in West Colorado Springs offering dry salt therapy, massage, yoga and occasional sound-healing or cacao ceremonies.

Lake Tahoe, California

Lakeside spa inside Tahoe Lakeshore Lodge in South Lake Tahoe, with a hot tub, polar plunge and dry sauna, by appointment only.