This is a common occurrence and not something you should be too worried about. During production, some heat that the machine generates can find its way to the exterior, which is not a problem. But if the machine remains hot to the touch even when it is not working, unplug it and contact the manufacturer for options on what to do. Most of the time, this problem is caused by an electric issue, but you want to rule out any damage to the machine itself. Do not attempt to repair the device as you may cause more damage or even void the warranty.