Poor, I find that you always have to switch through all stages until the device is back (0 - off, 1 - light, 2 - heat, 3 - light and heat). So at night the light goes on with, but if you shields the child's face, for example by hand, that's ok too. The pity is that the device does not switch off itself. To me it is sometimes happens that I just needed the light (level 1) and when I tried to make it, did not notice that I have switched to stage 2 (heat). Fortunately, I have it then but still somehow noticed.
Unfortunately, there is no real alternative for Bohrunwillige so I would buy the device again (must).