Where I live (in the southern U.S.) we don't get much wintry weather. Even a small amount of snow and ice can shut down the schools and make driving an iffy proposition. So, when we had a freak snowstorm a few years back, I thought it better to be safe than sorry and cancelled my piano lessons for the day, leaving phone messages for all of my students.
However, one student that lived close by didn't get the message. His father had a four wheel drive vehicle and they were out and about that day seeing the snow-covered sights. I had just settled down with a cup of cocoa when I heard the doorbell ring and saw a face peeping in the window. I sheepishly went to the door, still in my flannel PJ's, and let my student in. I told him I had cancelled lessons for the day, but if he didn't mind me teaching in my pajamas and fuzzy slippers we could go ahead and do our lesson! We all had a good laugh about it--but ever since I make sure to put on real clothes on snow days--just in case!