Hot water bottles are an underutilised domestic comfort, at least here in the south where we don't know what to do with ourselves when it gets cold, and don't even own boots. However, a hot water bottle can be a very good friend on a freezing night. I like to tuck a child up with one when they are feeling under the weather. It makes me feel like I'm doing *something*, and it certainly is cozy for the sick little person.
Every hot water bottle must have a cozy cover. Here is mine--I simply cut a rectangle of red flannel, folded it over, and machine stitched it down one side and across the bottom. Then I turned over enough fabric at the top to make a casing, and stitched that down with decorative green embroidery thread. For a drawstring, I ran red grosgrain ribbon through with plenty of extra to tie a big bow with. The cover comes off every time I fill it, to make sure it stays perfectly dry.
I would love to knit a cover some day out of a truly luxurious yarn, but in the meantime, my toes stay plenty warm with this one.
One last note--I'm showing off my schoolhouse quilt underneath the water bottle. My grandmother made it years ago to match the house!