Spas with reservation required

Austin, Texas

Hotel spa at Omni Barton Creek with steam room, sauna, cold plunge and a rooftop pool overlooking Hill Country, open daily 9am-7pm.

Scottsdale, Arizona

North Scottsdale day spa with massage, facials, sauna, steam and a thermal pool, plus private suites for couples and groups.

San Francisco, California

Hotel spa at The Huntington Hotel on Nob Hill with a heated soaking pool, sauna, steam room and terrace, open daily 8am-7pm; treatment booking required.

San Francisco, California

Neighborhood day spa in Noe Valley with a private outdoor hot tub, offering massage and a combined soak-and-massage package for two.

Hot Springs, Arkansas

Day spa on Central Avenue in Hot Springs offering massage therapy, facials and body treatments, with couples massage in a private suite as its signature draw.

Denver, Colorado

A Whittier day spa in Denver where private suites pair beer and wine baths with infrared saunas and a self-pour taproom.

Denver, Colorado

A Littleton day spa centered on private suites with beer and wine baths, infrared sauna, zero-gravity massage and a self-pour taproom.

Santa Fe, New Mexico

A 77-acre hot springs resort outside Santa Fe with spring-fed thermal pools, day-pass soaking packages from $175, and overnight lodging.

Palm Springs, California

A no-frills, family-run day spa on Indian Canyon Dr offering walk-in massage and foot reflexology from $40, open daily until 10pm.

Palm Springs, California

A men-only massage spa in downtown Palm Springs with private suites, a table-shower wet room, and about a dozen treatments including body scrubs and massage.

Palm Springs, California

Adults-only hotel spa at the Parker Palm Springs with 15 private treatment rooms, couples suites and a $300 signature aloe treatment.

Saturnia, Tuscany

Walk-in thermal park in the Maremma countryside with four outdoor sulfur pools, hydromassage jets and a vascular circuit fed by a 3,000-year-old spring.

Hudson, New York

Adults-only communal thermal baths and steam room in downtown Hudson, NY, with day passes, memberships and treatment-plus-soak packages.

Rishikesh, Uttarakhand

A compact Ayurvedic spa and yoga retreat near Laxman Jhula in Rishikesh, offering six treatments including Shirodhara by appointment only.

Shibu Onsen, Nagano

Reservation-only private hot spring and sauna suites at a Nagano brewery complex, built around a craft beer bathing plan for two to four guests.

Park City, Utah

A 14-room hotel spa at Westgate Park City Resort with a waterfall, sauna, steam room and thermal pools, open daily 9:30am-6:30pm.

Washington, D.C., District of Columbia

A Georgetown studio in Washington, D.C. offering private infrared sauna cabins and float therapy suites, bookable by reservation only.

Aspen, Colorado

Adults-only hotel spa at The St. Regis Aspen with Thai-inspired massage, 111Skin facials, an AI robotic massage, and a day pass covering pool, cold plunge, and

Cincinnati, Ohio

Day spa in Columbia-Tusculum, Cincinnati, with massage, facials, an infrared/Himalayan salt sauna and a $99 signature sampler package.

San Francisco, California

A reservation-only day spa in San Francisco's Marina offering private cold-plunge-and-sauna contrast suites and quiet float sessions, no walk-ins.

Boston, Massachusetts

A Seaport social wellness club in Boston offering saunas, ice baths, IV therapy, red light and HBOT sessions, with reservations required and no membership

Philadelphia, Pennsylvania

A head spa in Queen Village, Philadelphia, focused on scalp and hair treatments, with private suites and a $300 signature service.

Philadelphia, Pennsylvania

A Center City West day spa and salon on the Avenue of the Arts with two therapy suites that pair infrared heat or red light with salt air.

Napa Valley, California

Hotel day spa atop the Archer in downtown Napa with a water deck, fitness studio access and treatment rooms; reservations required.