system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Cryolipolysis, or 'Fat Freezing', how does it work? And does it work?
gpt
Cryolipolysis, or 'Fat Freezing', is fairly straight forward. It is a nonsurgical treatment that, effectively, targets certain pockets of fat and exposes them to cold enough temperatures to "kill" the fat cells. Although there are a number of methods to do this, such as Kybella (Deoxycholic Acid), through the use of a Laser and a couple other treatments, the most effective has been exposing fat to significant cold. What happens is that when subcutaneous fat is exposed to low temperatures, these fat cells can be damaged beyond the point of healing while not harming the skin. In a nutshell, chilling the fat cells below body temp but not to the point of freezing causes the fat cells being treated to die (localized cell death) that is removed by your body over the course of a few weeks. 

That said, this is the basis for how Coolscultping and every other Cryolipolysis treatment works. If you have an area of skin that contains fat cells that are treatable with 'Fat Freezing', a doctor or asthetician will hook you up to a thermal conduction/induction pad and apply low temperatures through the Cryolipolysis machine to the area being treated. They will make sure you don't undergo hypothermia or any negative cold exposure condition. A single treatment lasts about an hour and multiple treatments are generally needed to see the full effect. There are side effects, which can include redness in the skin, localized numbness and localized pain, all of which is normal and tends to go away after a month. Your doctor or asthetician will be able to futher tell you about all of the side effects. 

Does it work? That's the big question. The answer is that it does. It works - treatment in the right candidates has been shown to work quite well. Whether it works for you, however, is a different question. It depends on you. Obviously, there is the question about whether you are a candidate. To be blunt, treating a female patient who is 5'4", 300 pounds and is severely obease will not see results. Treating a male patient who is 5'10, 210 pounds will result in some positive effects from treatment. Your weight, the location of pockets of fat, where the treatments are targeting (ie Lovehandles vs. Stomach Fat), what kinds of fat you have (Subcutaneous vs Visceral) in a given area for treatment, etc. all have a huge effect on whether it will work. 

I do want to stress that this is not an alternative to diet and exercise. This is meant to contour the body, not serve as an alternative to actual medical care, proper health and nutrition.