Nope, just undies. Used to wear nothing, till I experienced my first middle-of-the-night earthquake here in California.
I know they recommend against trying to exit the building in an earthquake, but I'm in a ground-level studio apartment where the door to the yard is literally six feet from my bed, so I probably would run outside. If a big one hits in the middle of the night again, I don't want to run outside naked... so now I sleep in my underwear.