Spas with solo travelers

Day spa in Plainfield, IN offering facials, massages and body-sculpting treatments alongside a sauna, steam room and thermal pool, reservation required.

Two Indianapolis locations for cryotherapy, infrared sauna, Normatec compression and float therapy, with walk-ins welcome.

A Brentwood day spa focused entirely on scalp and head treatments, with private suites and a signature ritual built around halo water therapy.

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.

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

A moderately priced fitness-club spa in downtown San Francisco offering bodywork, skincare and specialty treatments with reservations required.