Looking up -- you realize that one of the twelve light bulbs of your living room chandelier has to be replaced. You turn electricity off, move a table to the center of the room, put a chair on top of the table and, new bulb in hand, you climb up on top of the chair. As you reach the chandelier, you notice that\ldots all bulbs look alike and that you have forgotten which bulb needed to be changed.\smallskip Restart all over again?\smallskip Luckily, an effortless creative solution exists. By just touching the light bulbs you can determine the cold one and replace it! Put differently, information about the device's malfunction leaked-out via its temperature...