Temperature at which the solid and liquid states of a pure substance can exist in equilibrium. As heat is applied to a solid, its temperature increases until it reaches the melting point. At this temperature, additional heat converts the solid into a liquid without a change in temperature. The melting point of solid water (ice) is 32°F (0°C). Though the melting point of a solid is generally considered to be the same as the freezing point of the corresponding liquid, they may differ because a liquid may freeze into different crystal systems and impurities can lower the freezing point.