What is happening here is strange, but the process can be understood if you think about water freezing. Water freezes at 32 degrees Fahrenheit (0 degrees C). If you were to stick a thermometer in a cup of water and put the cup in the freezer, you would find that the temperature of the water falls to 32 degrees F and then hangs there until all of the water is completely frozen. Then the temperature of the solid water falls to the temperature of the freezer.