Today's very important medical fact is that you can wear a hat in bed -- almost any kind of hat, except, possibly, a very broad-brimmed hat which might get crushed in the back. Still, you could wear a cowboy hat in bed, if you were a cowboy or wanted to be like one, or a frilly ladies hat with feathers.
I am mentioning hats, as possible, because at this hospital where I work -- you WILL get into out standard hospital gown, with your butt hanging out in the breeeze. You will not be wearing street clothes, nor shoes, nor pants, nor a belt, or a shirt or a blouse or a dress -- none of that.
But you can wear a hat.