Necessity is the mother of invention. My daughter was having bad cramps, which of course led to a google search for natural remedies. Before I knew it I was looking at old fashioned water bottles. They are rubber and ugly so naturally, I wanted to make a cover for it. Have you looked up warm water bottle cozy? There are so many hand made, knit, crocheted, recycled sweater and quilted cozy's out there.
Fill with warm water and cuddle with it under a quilt - yum! It can also be used with cold water for a sore back after sewing one for all of your friends :) Let me know if you make one, I would love to see it.