Just a sheet for me too. We set the a/c at a much higher temperature at night than during the day to save money. If it is REALLY hot the dogs don't even want to sleep next to me!

Bill Cosby once mentioned the need to sleep with a sheet in one of his comedy routines. He said with him it dates back to his childhood and the childhood fear of monsters. He felt that if he was under a sheet it provided protection. I always remembered this because I sort of felt the same way when I was little. My sheet was good protection from things that go bump in the night.