Kimberly what a great idea. I make some for our local shelter. They don't have requirements like hospital quilts or kids charities. They do have some "likes"--they like them to be flat with just an old blanket or towel for batting (no regular quilt batting). They also like them to be a size that's able to fit in their washing machines. Check with the shelter and they'll help you out.
I just sewed together some old samples of men's suiting (OMG some were cashmere). Used an old beach towel for batting, flannel sheet for backing. Sewed it all together and turned it right side out. It was 28 x 28 inches square.
Good luck!