We’ve come to accept that there’s “good” cholesterol and “bad” cholesterol, said Alan Bavley in The Kansas City Star. Now, thanks to three new studies in The New England Journal of Medicine, we’ll learn a similar distinction for fat. The “bad” kind, white fat, is what you see clumping around your waistline, but active brown “good” fat—previously thought to disappear after infancy—actually works to burn white fat, even in adults.

If researchers come up with a way of stimulating your brown fat, said Daniel DeNoon in WebMD Health News, “you could lose 9 pounds or more of bad white fat every year—without having to eat less or exercise more.” Think of the potential for new obesity therapies! Brown fat becomes active in low temperatures, when it warms you up by burning white fat as fuel, so until science gets a breakthrough you can at least lower the heat.

“Before we all turn our thermostats down or consider joining the Polar Bear Club,” said Alice Park in Time, we should let scientists gather more information. Nobody knows, for example, why women are twice as likely as men to have active brown fat, or if a successful pill to activate the fat would “throw off other metabolic systems” and do more damage than good.