Color Changing radiator

Our home resembles a living creature in many aspects. It changes constantly as we live our daily lives within it. Within its walls, hot water pipes and electrical wires wind their way, very much like the nerves and veins inside the human body. The veins carry warm blood, regulating the temperature of the human body. The radiators carry warm water which maintains the correct temperature of our home.
The radiator is made of cast iron and painted with a coating which changes colour according to temperature. When cold it is blue, but blushes with red when above 30°C.