Actually ordinary water is not so ordinary after all.It changes heat transfer properties at certain temperatures, As it drops in temperature, it reduces in volume as any liquid does, until it freezes when it then expands. Unlike many liquids it does not become more viscous as it approaches its freezing point. Conversely, it will never raise past 100°C as it will just boil. Amazing properties for an amazing compound. And it is a key ingredient in beer, something which is enjoyed worldwide.