Why the temperature does not change …

We know that phase changes occur when materials change state, going from liquid to solid (as when water freezes), solid to liquid (as when rocks melt into lava), liquid to gas (as when you boil water for tea), and so on. When the material in question changes to a new state — liquid, solid, or gas — some heat goes into or comes out of the process without changing the temperature. You can even have solids that turn directly into gas. As dry ice gets warmer, it turns into carbon dioxide gas. This process is called sublimation. Imagine you’re calmly drinking your lemonade at an outdoor garden party. You grab some ice to cool your lemonade, and the mixture in your glass is now half ice, half lemonade (which you can assume has the same specific heat as water), with a temperature of exactly 0 degrees Celsius.