What it is: Infrared saunas, a new take on an old relaxation idea.

Unlike traditional saunas, infrared saunas don't use steam to heat the air. Instead, they create light rays that produce heat. As a result, your body is heated from the inside, raising your core body temperature and causing you to sweat.

This trendy spa treatment has been embraced by celebrities such as Lady Gaga and Jennifer Aniston, who credit it for glowing skin and for healing chronic pain.

Description: Awaken for Wellness Spa in St. Paul has four infrared saunas. They are not as hot as a traditional sauna, where temperatures often range from 180 to 200 degrees Fahrenheit, said Jesse Steinmaus, manager and owner of Awaken. Infrared saunas typically fluctuate between 120 and 150 degrees. The maximum allowed at Awaken is 158 degrees.

How it works: First-time users are limited to 30 minutes; after that, the maximum goes up to 40 minutes. Cutting the first session short allows the body to become acclimated to the process, said Steinmaus, adding that the infrared sauna raises your core body temperature by up to 3 degrees above normal body temperature. The sauna is in a private room, and you can adjust the heat as needed. You also can listen to music or watch Netflix videos while sitting in the sauna.

What to bring: Two towels — one to sit on and one to wipe your body dry. Also, bring a bottle of water and a pair of sandals.

Health claims/warnings: Regular users claim infrared saunas can improve circulation, lower blood pressure, relieve muscle pain and stimulate the immune system. They have also been associated with relief of inflammation caused by Lyme disease.

Because the heat is less stifling than in a conventional steam sauna, it is easier to tolerate sitting in one for longer periods. That can make it hard to tell if you're overheating. Steinmaus advises clients to drink plenty of water to avoid dehydration and to listen to their bodies.

What it felt like: On a 1-degree morning, I was eager to warm up in a hurry. I stepped inside the cedar-paneled infrared sauna, starting out at 140 degrees. Beneath glowing blue lights, I started to sweat — a little at first, then much more after I selected the 158-degree maximum.

After 30 minutes, I was invigorated.

Cost: A single session is $30 (new clients pay $20 for one session). Or you can purchase a package of sessions, ranging from $125 for five to $480 for 30. Membership fees range from $65 a month for five monthly sessions to $155 a month for unlimited sessions.

Location: Awaken for Wellness, 1821 St. Clair Av., St. Paul; awakenforwellness.com, 651-493-0459.

Allie Shah • 612-673-4488