My sister is on dialysis and I am making her a quilt too. She has a small one that the center gave her but it is not quite large enough to keep her warm. When they remove all their blood to filter and clean it, it is returned to the body at below body temp besides the fact that the rooms are kept cool just like an OR is at the hospital to help with the germs and the heat that all the equipment puts off. One thing that needs to be remembered is that these quilts will get a lot of use and laundering so they need to be sturdy and well constructed. I know that my sister has extremely dry skin since her dialysis and the flannel or fleece would not be great for her so I am sticking with cottons and a thin low-loft batting like I would put in a baby quilt that can handle the laundry conditions it will experience.