Spas with reservation required

Williamstown, Massachusetts

Day spa in a converted 1762 grist mill on the Green River in Williamstown, offering massage, facials and a private outdoor hot tub.

Scottsdale, Arizona

A moderately priced day spa in South Scottsdale with lake-view suites, massage and facials, plus a dedicated couples treatment room.

Oslo

Waterfront sauna spot on Aker Brygge with shared and private saunas, sea bathing, and sauna boat trips on the fjord.

Boston, Massachusetts

A Finnish kelo-log banya in Newton with sauna, steam room and cold plunge, alternating men's and women's days, day passes from $69.

Bishop, California

A century-old natural hot springs pool near Bishop in the Eastern Sierra, with a cooling waterfall, a separate hot soak, and simple day-use facilities.

Portland, Oregon

A membership-driven wellness club in downtown Portland with hot pools, sauna, steam room and cold plunge, plus massage, skincare and fitness classes.

Indianapolis, Indiana

Day spa in Allisonville, Indianapolis with sauna, steam room, thermal pool and cold plunge, plus about 10 massage and facial treatments for solo visits or

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.

Miami, Florida

An upscale day spa on Miracle Mile in Coral Gables with sauna, steam room and cold plunge, known for a $200 signature treatment and couples packages.

Port Douglas, Queensland

Day spa in Port Douglas with sauna, steam room, thermal pools and cold plunge, offering massages, facials and body treatments by appointment.

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.

Hudson Valley, New York

A Newburgh day spa built around a Japanese head spa signature treatment, with massage, sauna, steam room and pool access, open seven days a week.

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.

Austin, Texas

Eco-friendly day spa in Anderson Mill, Austin, offering organic massage, facials and body treatments with a sauna, steam room and cold plunge.

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.

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.

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

Scottsdale, Arizona

Recovery-focused studio in South Scottsdale centered on a cold plunge, hot tub, infrared sauna, compression therapy and red light rooms rather than traditional

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.

Charleston, South Carolina

A Mount Pleasant recovery studio near Charleston offering cryotherapy, compression therapy and infrared sauna sessions, open daily except Sunday.

Denver, Colorado

A small European-style bathhouse in Denver where you rent a private sauna by the hour and share a cold plunge, cold waterfall bucket and steam room.

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

Dallas, Texas

A membership-based recovery studio in Dallas's Cityplace offering cryotherapy, infrared sauna, compression, IV drips and skin treatments by reservation only.