One of the buzziest (and most popular) professional cold treatments is this so-called "fat freezer," performed at dermatologists' offices. It uses freezing temperatures to single out fat cells and crystallize them, killing the cell. Yes, killing. As in, no more fat cell.
While CoolSculpting isn't the only treatment for fat reduction, it is the only one to freeze the cells instead of heating them. "All the cells in our body have a temperature threshold," says Laura Dyer, MSHS, PA-C at Dr. Amy Wechsler Dermatology in Manhattan. "With heat, in order to get to an efficacious temp it is usually quite painful because it is not only very hot, but it's a little less consistent."
CoolSculpting, on the other hand, uses a temperature slightly higher than what water freezes at, so it just targets the actual fat cells and not the water-based cells surrounding it. This means less bruising, swelling, and pain.
As fat-freezing guinea pigs, we can personally attest to that statement. Recently Zeltiq, the maker of CoolSculpting, upped its game by tweaking some of its applicators to make the temperature one degree Celsius cooler. Dyer notes that this allows the treatment to be 25 minutes shorter and could even boost the results of some clients' treatments.