Warm On is still a concept, but I am eagerly awaiting its release on the market. The idea here is that if your bathtub’s temperature is kept at a constant warmth, you will waste less water. Which makes sense. Warm On is a pebble-like gadget that contains a heater. All you have to do is drop it in your tub, and it works to maintain the water’s warmth. It appears that you can set a timer, which would be good for people like me who sometimes get lost in a book and forget we really shouldn’t stay in the tub indefinitely.
The concept behind this is based on that of a submarine volcano, where water flows over the magma and heats up. Much like a submarine volcano, Warm On lives on the bottom of your tub, and water enters through an opening in the device to be monitored for temperature. If it gets too cool, the heater will kick in.
I really, really want one.