The only time I've ever worn a hat to sleep is when my brother, a few buddies of ours, and I decided to winter-camp overnight on a 300-mile snowmobile trip. Sounds like a dumb idea, but truth be told, if you're someone who is always warm, you will sleep really well with the proper precautions. My biggest complaint of the whole thing was not having a fan to sleep with, which left me to listen to the clicking sound of the tinnitus in my left ear. Personally, give me gym shorts and a t-shirt. I can wake up and go to the corner gas station for a cup of coffee, and all I need are my keys, bank card and a pair of sneakers--out the door in under a minute. Plus, if I ever forget to take out the trash Thursday night, and I hear the garbage truck coming Friday morning, I can dash out and run the trash bags to the curb without offending the neighbors. Luckily enough, the garabge man comes down my street twice, so if he sees something new on the side he already did, he's cool enough to swing over and grab it.