Self-heating face masks are at the very top of our list of “beauty products most likely to be witchcraft.” These treatments, which warm up upon contact with the skin, have earned themselves a permanent place in our skin care rotations thanks to their unprecedented ability to smooth skin texture and draw out pore-clogging debris. But just how they work has always been somewhat of a mystery.
The short answer? Chemistry. The self-heating thermal process is actually a chemical reaction: Some chemicals, when exposed to water, produce an exothermic response that instantly generates heat. You know you’d use a hot compress or a steam treatment to open your pores and get a deeper clean; well, these self-heating products work in the same way to better detoxify the skin.
Bioré Self Heating One Minute Mask ($7.99), for instance, gets its thermal power from zeolite, a naturally occurring mineral derived from volcanic rocks and ash. “Upon contact with water, [the] chemical bonds [in zeolite] are broken, and energy is released as heat,” explains Erica Palmer, R&D skin care group leader at the Americas Research Labs of Kao USA, which manufactures Bioré. Somme Institute Boost Warming Mask ($40) also uses zeolite as its active ingredient: “The warmth is activated when massaging Boost on facial skin, [which] releases the action of zeolite,” says Edward Fallas of Somme Institute.
But why should you opt for a self-heating mask in favor of your run-of-the-mill temperature-stabilized formula? “Self-heating masks are essential to open pores and activate blood circulation,” Fallas explains. If you suffer from blemishes, clogged pores, or oil overproduction, the enhanced pore-opening, blood flow–boosting action is perfect for you—and it enables the other ingredients in the treatment, like oil-absorbing kaolin (which is in both formulations), to work deeper within the skin to absorb impurities and debris.
As cooler weather creeps in on us, these heating masks seem more appealing than ever: The sensation is ridiculously relaxing, especially in combination with a luxurious soak in the bathtub. So the good news is that the self-heating action really does help to make the ingredients more effective. The bad news is that now you have all the more reason to spend money stocking up.