Spas with upscale

Palm Springs, California

Adults-only hot springs resort on Miracle Hill in Desert Hot Springs with private mineral tubs, a Finnish sauna, salt room and 35 spa treatments.

Miami, Florida

Day spa in the Sherry Frontenac Hotel's lower lobby in Miami Beach, with sauna, steam, cold plunge and thermal pool alongside massage treatments.

Miami, Florida

A beachfront resort spa in North Beach, Miami with cryotherapy, a floating salt bath, sauna, steam and a cold plunge, open to walk-ins and day-pass guests.

Miami, Florida

Hotel spa inside Dua Miami, Autograph Collection in Brickell, open daily 9am-6pm, with sauna, steam room, cold plunge and couples massage rooms.

Miami, Florida

Adults-only spa and pool complex inside Loews Miami Beach Hotel, open to hotel guests only, with sauna, steam, cold plunge and thermal circuits.

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.

Napa Valley, California

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

Sonoma, California

A boutique day spa in downtown Sonoma centered on infrared sauna and cold plunge drop-ins, plus massage, red light and PEMF therapy.

Napa Valley, California

Adults-only resort spa built into a wine cave in Napa, with a vineyard-view pool, sauna, steam room and hot tub; reservations required.

Palm Springs, California

Hotel spa at Agua Caliente Rancho Mirage with day passes for the sauna, steam room, salt rooms and private spa pool.

Calistoga, California

Hotel spa in downtown Healdsburg with a garden patio, jacuzzi and pool access, open daily 9am-5pm for guests and day visitors.

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.

Napa Valley, California

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

Calistoga, California

A 20,000-square-foot resort spa in Calistoga with five geothermal pools, Calistoga mud treatments, and a day pass for non-hotel guests.

Orlando, Florida

Adults-only hotel spa at the Hilton Orlando with a sauna, steam room, cold plunge and thermal pools, plus couples treatments and HydraFacials.

Scottsdale, Arizona

Adults-only hotel spa at W Scottsdale with thermal circuits, sauna, steam, cold plunge and a robotic Aescape massage option.

Bridgetown, Christ Church

Hotel spa at Accra Beach Hotel in Christ Church, Barbados, with six treatment rooms, a sauna and steam room, open daily 8am-7pm for hotel guests.

Calistoga, California

A 1952 Calistoga hot springs resort with three mineral pools at 85, 95 and 104°F, mud baths, overnight rooms and a day-pass option.

Hilton Head Island, South Carolina

Hotel spa inside an oceanfront Hilton Head resort, offering massages, facials, body treatments and manicures to overnight guests.

Sonoma, California

Hotel spa at The Lodge at Sonoma with an outdoor terrace, soaking pool, plunge pool and barrel sauna, open daily 9am-5pm, adults-only, reservation required.

Sedona, Arizona

A resort spa at Amara in Sedona with outdoor baths, an infinity pool and a relaxation lounge, open only to hotel guests.

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.

Dallas, Texas

A hotel spa at Omni Las Colinas in Irving, Texas, with an outdoor pool and bath area, open to hotel guests along Lake Carolyn.

San Diego, California

A resort spa on a 44-acre Mission Bay island in San Diego, open to hotel guests, with sauna, steam room and pool access.