I'm traveling somewhere, and we're staying in this very old room, almost like a castle, with a very high ceiling. The people who are staying there with me look it up online and note that the tiles can fall from the ceiling, dangerously.

Almost as soon as we know that, one of the rectangular tiles falls, and drifting a little bit, crashes onto the bed, shattering. It doesn't hit anybody, but if it did, it would be very bad, perhaps deadly. Soon another one falls, and it's getting pretty scary. I consider what we have available that we could put over ourselves to protect us from the tiles while sleeping.