Though you can indeed clean your shaver head with both hot and cold water, the experts at Phillips suggest that warm/hot water is preferable. This is claimed to be more effective at removing what’s left over in the shaver and offers a better performance every time afterward. Philips say that you should rinse the top part of your shaver head for at least 30 seconds under warm running water for the best clean. Then, attach the head back on to your shaving head, only when it is completely dry.