RICE--rest, ice, compression, elevation--
Are implemented as soon as possible after acute injury or surgery to reduce inflammation, pain, and to help stop bleeding by vasodilating the blood vessels. They can also be used to keep bruising from getting worse, and heart surgeons have even begun to use a "brain freeze" technique with a nose spray that they use for heart attack patients in the ambulance to reduce the spread of brain damage. I looked further into this when my father had a stroke and bleeding on the brain. This is my next venture and I think cold will be implemented more in the future. And, you guys may recall cold being used on the Buffalo Bill that broke his neck. His surgeon put him in a hypothermic state, which prevented some injuries from worsening, and he is doing well today. The surgeon was lauded by many, but others would prefer to go by studies from 20 years ago to base their opinions.
Actually, the system I have is iceless and only goes to 43 degrees, which is even better because it leads to compliance and is safer for the skin/nerves, and patients can wear it longer.
If there is inflammation, cold reduces it, specifically if there is a little compression or vasopneumonic device that pushes out edema and swelling. I don't care what a study says.
We work with @ 70 surgeons and some of the biggest names in the SE. They wouldn't use it if it didn't reduce swelling and pain.