While there are plenty of skin-boosting benefits to be gleaned from working out, your sweat sesh can also have the opposite effect on your birthday suit. An occasional hot yoga class does your body good, but experts are finding that taking classes too frequently—AKA multiple times per week—might not be good for your complexion.

“We used to think UV rays were the only external cause of skin damage, like age spots, but a growing body of research tells us that’s just not true,” Doris Day, MD, a clinical associate professor of dermatology at NYU Langone Medical Center in New York City, told Allure. “Spin instructors and women who were taking hot yoga upwards of five times a week were getting more discoloration and persistent redness than other patients.”

But how is that even happening? Zoe Diana Draelos, MD, a consulting professor of dermatology at Duke University, says it all has to do with how heat interacts with skin cells.

“We now know that heat triggers melanocytes, the pigment-producing cells within our skin, to create the pigment that causes age spots as a defense mechanism,” says Dr. Draelos. “Melanocytes react when they’re injured, and heat is a form of injury.”

Before you go cancel any of your favorite classes, there is something you can do to help prevent damage to overheated skin. First, add some variety into your schedule to balance out the heat-heavy workouts with ones that won’t leave you feeling like a hot, sweaty mess.

And when you do take hot yoga, go on a run, or head to a spin class, Dr. Day recommends taking an icy shower or using a refrigerated mask afterward to bring your skin’s temp back down to normal. Just do it as soon as possible after your workout to prevent the most damage.

Otherwise, Dr. Draelos says wearing a foundation containing the minerals titanium dioxide, zinc oxide, iron oxides, or kaolin during a hot workout also helps block out the infrared heat—but, if you’re worried about clogging pores, a good old ice bath might reign supreme as a skin-saving regimen.