There was an insulating charm. Why hadn't anyone thought about using this charm when the cold weather started? They all had to do the charm several times to get it to work, and even then it might not work because of the cold? Maybe it would work with everyone doing it. At least it might help with smaller areas if it did not work for the whole castle. She could try it on the dormitory. Picking up her quill, she took notes on the charm.
Now to practice the incantation.
"CAY-lum SAY-peee-oh. CAY-lum SAE-pee-oh. Caelum Saepio."