[lupire]

At melting, the energy is going into the state change.

[eyelidlessness]

And the state change occurs when the portion of solid ice becoming liquid water warms however slightly, even if there’s a cooling side effect on the remaining ice as more energy is dissipated during that warming. Or am I still misunderstanding?

[topaz0]

Yes. It is literally an isotherm. Energy is added without changing the temperature.