If left on one area for too long it will make the skin peel for the next several days. My dermatologist uses the dry ice from a small cylinder (like a miniature oxygen tank) every few months when I go for my rosacea. I also have acne which it helps too because it is a chemical peel basically. However if your skin peels or becomes too red see another Dr. They shouldn't be using it that aggressively. My face is a little red afterwards but that is usually it. Once he did it too long in one place & it did peel but that was the only time it happened.
Yes, and it will do permanent damage to the skin as well. If you touch it, you should seek a doctor to make sure that you aren't burned terribly. Hope this helps, good luck to you.