This time of year is filled with opportunities to pack on extra pounds. Think Christmas cookies, eggnog, lazy days when your only exercise is shuffling from the couch to the fridge … you get the idea. But if you live in a cold-weather climate, you have at least one calorie-burning weapon in your holiday arsenal: that arctic blast that hits you when you step outside.

Yup, cold temperatures can boost calorie burn. We already knew this, thanks to recent studies on brown fat and the hormone irisin, both of which are involved in energy expenditure and are activated by involuntary muscle contractions—like shivering when the temperature drops.

But we love how the American Chemical Society spells out the science for us in this new video, and shows us exactly how the process goes down. It’s a great reminder of how hard our bodies are working beneath the surface, even when we’re barely moving a muscle.

To be clear, shivering on a ski lift or waiting on line outside a movie theater could never provide all the benefits of an actual heart-pounding, muscle-building workout—which can also, by the way, trigger brown fat to burn more calories. But at least we can take heart in knowing that it may help—even in the tiniest way—keep off some of that dreaded winter weight.