In the UK, we still have requirements for windows to be open. This year it's much better because they decided to introduce carbon dioxide monitors to every room

In the UK, we still have requirements for windows to be open. This year it's much better because they decided to introduce carbon dioxide monitors to every room and force teachers to figure out how to leave the windows open and still have it below an acceptable level. In December 2020, there was no such scheme, just all the windows open in all classrooms, in the winter. It was especially difficult for most students because while sane schools might've allowed students to wear coats, we had no such luck, only school uniform which is as good as a t-shirt.