Wellness Rooms With Hot and Cold Vitamin C A restful vacation is obviously good for you, but can your hotel room alone make you feel better? The MGM Grand Hotel & Casino in Las Vegas thinks so. Forty-one of the hotel's 5,044 rooms have been designated StayWell, with features that the wellness real estate firm Delos developed. The rooms, open to guests on Oct. 15, include extra soundproofing, ventilation that purifies and humidifies the air, and filtered water on tap. Bathroom lighting emits blue light said to counter jet lag, and a vitamin-C-infused shower (right) is intended to filter out chlorine. The rooms, which start at $105, $30 more than usual, will be cleaned using hypoallergenic products, and guests will be able to use wellness tools - like apps that promote healthy cooking and eating habits - developed by the Cleveland Clinic for 60 days after their stay. But does it work? "It's hard to know without conducting rigorous tests," said Dr. Richard Sloan, professor of behavioral medicine at Columbia University Medical Center, which was involved in research on the features. But I'm convinced some of the amenities are desirable and can have measurable benefits.