My late DH was a Boy Scout Master, and had one little boy about 12 who told me that he had arthritis so bad he didn't sleep well, but found that the even warmth of a down sleeping bag let him rest better at night. This was even better than a down comforter he told me. His parents had tried everything but since using his Scout sleeping bag, his nights were more restful.
I think he had to roll it up and keep it in a closet during the day.