What happens to temperature during a material's change of state?

During a material's change of state, such as melting or boiling, the temperature remains constant even though energy, in the form of latent heat, is being absorbed or released. This is because the energy is used to break intermolecular bonds rather than to increase the kinetic energy of the molecules, which is what would raise the temperature.

For example, when ice melts to become water, the temperature remains at 0 degrees Celsius until all the ice has melted. Once the transition is complete, any further energy added will then increase the temperature of the water. The phenomenon is fundamental to understanding phase changes and the concept of latent heat, where energy is put toward changing the state rather than increasing temperature.