Spas with reservation required

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.

Houston, Texas

A Houston day spa near Memorial Park offering massage, facials and spa packages, with a sauna, steam room and pool on site.

Dallas, Texas

A Knox/Henderson day spa offering massage, facials, waxing, and recovery extras like infrared sauna and cold plunge.

Napa Valley, California

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

Saratoga Springs, New York

Historic 1935 bathhouse in Saratoga Springs offering mineral water soaks and massages in original tubs, reservation only, moderate pricing.

Mexico City, Quintana Roo

A Japanese-style hotel spa in Mexico City's Cuauhtémoc district with tatami suites, outdoor onsen baths and a $2,080 day pass for couples.

Milford, Ohio

A small, adults-only day spa in Historic Old Milford with a salt room, massage room and red light therapy, booked by reservation.

Indianapolis, Indiana

A moderate-priced day spa in northwest Indianapolis offering float therapy, salt room sessions, infrared sauna, cold plunge and foot detox, closed Mondays.

Santa Fe, New Mexico

A small Santa Fe day spa centered on a halotherapy salt room, with sauna and ionic foot detox add-ons, booked by reservation only.

Scottsdale, Arizona

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.

Seattle, Washington

Japanese-style head spa in Belltown offering scalp treatments and bodywork from $55, open daily 10am to 10pm, reservations needed.

Colombo, Western Province

A hotel spa inside The Kingsbury Colombo offering Balinese and Thai-style massages, facials and body treatments, with couples packages.

Portland, Oregon

A reservation-only head spa in Vancouver, WA, just across the river from Portland, focused on scalp, face and hand treatments plus a post-service relaxation

Naples, Florida

A small, moderately priced day spa in East Naples offering massage and a sauna, open daily with walk-ins accepted.

Asheville, North Carolina

A Japanese-inspired destination spa on a mountainside outside downtown Asheville, built around private outdoor salt hydrotherapy tubs and massage.

Sierraville, California

A non-profit hot springs retreat near Lake Tahoe with natural spring pools, reservation-only day and evening soaks, camping and rooms, closed Mondays and

Carmel-by-the-Sea, California

Upscale day spa in Carmel-by-the-Sea's Golden Rectangle with sauna, steam, cold plunge and thermal pools, open daily from 6:30am.

Asheville, North Carolina

A boutique day spa inside Haywood Park Hotel in downtown Asheville, offering facials, massage and couples treatments with free valet parking.

Seattle, Washington

A reservation-only social wellness sauna spa in Renton (serving the Seattle area) with a thermal pool, cold plunge, sauna and steam room, day passes from $75.

Mumbai, Maharashtra

An upscale Ayurvedic retreat in Vile Parle West, Mumbai, with five treatments, couples rooms and a relaxation lounge; reservations required, open daily

Santa Barbara, California

A downtown Santa Barbara day spa built around a private infrared sauna, salt room, cold plunge and a sound-and-light meditation pod, booked by appointment.

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.

Dallas, Texas

Hotel spa inside The Adolphus in downtown Dallas, with six treatment rooms, a couple's suite and a 22-item menu of massages, facials and body treatments.

Carmel-by-the-Sea, California

Resort spa at Carmel Valley Ranch with 12 treatment rooms, private terraces, a saltwater pool and infinity hot tub, open to adults by reservation.