A heated classroom, fire playlists, and burning abs and glutes are what make Hot Pilates so hot right now. Devotees of the sweaty mashup include professional dancers, triathletes, and yogis wanting to build strength for more solid Chaturangas. Beginners will make it out alive, just know that Child's Pose is your best friend.

Having already taken over the South Bay, where Yoga Source in Los Gatos warmed up the trend, Karma Yoga, in Cow Hollow, is the first San Francisco studio to take the principles of classical Pilates (strong core and glutes) to the next level with intervals, squats (soo many squats), and lunges in a heated room (90 to 95 degrees) at 30 percent humidity.

What happens in an actual class?

The instructors at Karma Yoga normally open a 60-minute session with a bridge series that seems innocuous enough—some basic seat work in a warm room. But then it keeps going, set after set, with movements getting tweaked just enough for an additional round of reps, so that by the end of this "warm up" your tush has been thoroughly worked from every angle possible. In the 40 or so minutes between this glute series and a similar extended core series at the end of class are full bodyweight moves and two sets of high intensity interval training (HIIT) to make sure you're drenched in sweat and won't be able to walk up stairs or laugh without some after-burn. (My abs felt it for three days.) The whole sequence is set to energetic playlists that help push you all the way to your edge.

Carrie Brackin, proprietor of Karma Yoga and teacher of the toughest Hot Pilates class at the studio, says the reason for the heat is to "warm up muscles quicker, so that more movement can get done during class. In a cooler room, muscles don't warm up as much and we want the body warm the entire time so that even low impact movements are intensified and joints are looser for more mobility."

In the past couple of weeks that I've been practicing Hot Pilates, I've noticed that I can lift a little heavier on my weight lifting days and hold a plank a little longer, a little more comfortably. "I didn't think I could have a yoga studio without Hot Pilates," Brackin says, "because the strength and flexibility of each really complement one another." I totally get it, as stacking these two methods during the week has become my new favorite ying-yang go-to. (Warning: Do not take this class after a blowout—dry shampoo can only do so much.)

For a seriously sweaty full-body workout, check out a Hot PIlates class at one of these Bay Area studios:

Karma Yoga, 1906 Union St. (Cow Hollow), karmayogasf.com

YogaSource, 16185 Los Gatos Blvd. (Los Gatos), and 158 Hamilton Ave. (Palo Alto), yogasource.com

Vibe Yoga, 3750 Florence St. (Redwood City), vibeyogaca.com