In the past, treating second-degree burns was a long process, and infections were hard to avoid. To replace the lost outer skin, grafts have to be grown, either artificially or taken from another part of the patient's body. These grafts are very thin, a sheet only a cell thick. These grafts are easily damaged, are prone to infection, and take weeks to fully heal a burn. A new prototype technology, the skin gun, may make the healing process a lot less painful.
It's an amazing innovation, but a simple idea. Stem cells develop rapidly into all the necessary types of cells, and are ideal for this sort of application. National Geographic made a good video explaining how this works, and featuring a real patient who has had the procedure done. The results are spectacular. I've embedded the video below; however, take note that it does contain graphic images of second-degree burns, which are not for the faint of heart or stomach. Click to see the video below.