Spas with reservation required

Carmel, Indiana

A no-frills contrast therapy studio in Carmel, Indiana, built around a 30-minute sauna-and-cold-plunge circuit for solo visitors.

Milwaukee, Wisconsin

East Town Spa in Milwaukee's Juneau Town combines a full-service salon and med spa with a thermal circuit of sauna, steam, pools and cold plunge.

South Jordan, Utah

A day spa and wellness center in South Jordan, Utah, with a salt room, infrared sauna, cold plunge, float therapy and a yoga studio.

Ubud, Bali

An adults-only wellness retreat on Ubud's Ayung River offering multi-day healing programmes, thermal circuits and plant-based cuisine by reservation only.

Tucson, Arizona

Day spa in Tucson's La Encantada shopping center with a thermal circuit of sauna, steam room, cold plunge and soaking pools.

Scottsdale, Arizona

Hammam-inspired hotel spa at Omni Scottsdale Resort & Spa at Montelucia in Paradise Valley, with private suites and massage, facial and body treatments for

Sonoma, California

A moderate-priced day spa a block off Sonoma Plaza offering massage and facials from a certified therapist and licensed esthetician, with private treatment

San Diego, California

A Clairemont wellness studio in San Diego pairing acupuncture and bodywork with an infrared sauna and a Himalayan salt room for classes.

Santa Barbara, California

A State Street halotherapy spa built around a large underground crystal salt cave, with massage, facials and a relaxation lounge.

Transylvania County, North Carolina

All-inclusive multi-night wellness retreat in Pisgah Forest, NC, combining fitness classes, spa treatments, guided hikes and farm-to-table meals in private

Minneapolis, Minnesota

A moderate-priced day spa in Minnetonka with a sauna, steam room, thermal pool and cold plunge, set up for couples and adults-only visits.

San Diego, California

A budget-friendly massage and medspa in Core-Columbia, San Diego, with private suites, a sauna and a couples treatment room.

Lake Tahoe, California

A wellness center in Kings Beach offering massage, yoga, acupuncture and counseling, open daily with walk-ins and reservations accepted.

Carmichael, California

A single-room salt cave in a Carmichael strip mall offering 45-minute salt therapy sessions for relaxation and respiratory relief.

Palm Beach, Florida

An oceanfront resort spa in Riviera Beach combining Ayurvedic treatments with a hydrothermal circuit, hammam, salon and private beach access.

Lake Tahoe, California

A wellness studio in Tahoe City offering reiki, massage, meditation, sound healing and yoga classes, open daily from 9am to 7pm.

Encinitas, California

Adults-only day spa in Leucadia, Encinitas, about a mile from the beach, with private suites, a relaxation lounge and movement classes.

Maui, Hawaii

A nine-room resort spa on Maui's Road to Hana offering lomi lomi and lava-stone pōhaku wela massage, plus a eucalyptus steam room and cold plunge.

North Royalton, Ohio

A North Royalton day spa built around a salt room and sauna, with adults-only halotherapy sessions on a walk-in or reserved basis.

Albuquerque, New Mexico

Hotel Zazz is an adults-only boutique hotel in Albuquerque's Nob Hill district with an on-site spa, heated pool and speakeasy lounge.

Las Vegas, Nevada

Float tank, massage and salt therapy spot in Peccole Ranch, Las Vegas, open daily with walk-ins accepted alongside bookings.

Ojai, California

A small, independently owned day spa in Ojai offering facials, massage, head spa treatments, infrared sauna and salt therapy.

Naples, Florida

Day spa in Central Naples with a salt cave for halotherapy, plus massage, facials and yoga classes; walk-ins welcome but reservations recommended.

Los Angeles, California

A wellness retreat in Westlake's Wilshire corridor offering cold plunge, sauna and movement classes, built around group and community sessions.