Heating water takes a great deal of energy. We say that water has a high specific heat. It can absorb lots of energy before its temperature rises. This is why water is such a good option to use in cooling systems–moving heat energy away from where it is not wanted. But water is, therefore, also good at retaining heat. It needs to lose lots of energy before its temperature decreases. This makes water equally useful in heating systems-moving heat energy to where it is needed. This challenge explores water as a heat transfer mechanism.