Napping for $150. Beneficial to Health.

Sleep-deprived Americans are increasingly turning to the power nap and afternoon siesta to restore alertness and enhance performance, studies show. And here's an eye-opener: Spa patrons are shelling out big bucks just to snooze.

The Kohler Waters Spa at Burr Ridge, which opened in April, offers a 60-minute massage with a 15-minute restorative nap service for $150. Meanwhile, Yelo, a New York City spa with air-conditioned sleep chambers, plans to open a Chicago location in 2009 or 2010, according to the company.

"We are seeing so many of our guests coming in that are having trouble sleeping at night," said Jean Kolb, Kohler's wellness business director. "This is a way for us to really extend an opportunity for them to have total relaxation."

But a catnap may not be the answer to bedtime bliss. Some sleep scientists say napping can negatively affect nighttime sleeping and make you groggy. Meanwhile, other researchers say dozing can relax, rejuvenate and improve health.

Still, other napsters prefer a fancier snooze. The Kohler spa in Burr Ridge has performed more than 50 custom massages with restorative naps since the spa opened April 21, Kolb said. After their 60-minute massage, spa patrons stay on the massage table, and the massage therapist covers their eyes with a warm aromatherapy towel and lowers the lights. Patrons are awakened 15 minutes later to the sound of a tuning fork and bowl.

In New York City, the Yelo spa charges $15 for a 20-minute nap in its YeloCab, a private space with a reclining chair, cashmere blankets and purified air. Customers chose the color and intensity of the light in the cabin and their hibernation sounds (environmental or music).

Pamela Spiegel, a Yelo account executive, said the company plans to expand to Chicago in the next two years but a location has not yet been picked.

A six-year study released last year by the Harvard School of Public Health and the University of Athens Medical School in Greece found midday napping at least three times per week for at least 30 minutes reduced heart disease deaths by about one-third among men and women. The study focused on 23,681 Greeks who had no history of coronary heart disease, stroke or cancer.