Leaping into a hot shower of a morning is invigorating, refreshing, warming, all sorts of things. What you don't want it to be is freezing. Now of course you could just use your hand to test the temperature of the water - but where's the fun in that? This shower light incorporates a temperature sensitive light source, so not only can you shower in streams of light, but the light changes according to the temperature of the water. If the water is cold then the light will glow blue and if the water is 32°C then it will glow red.