Hot Water Bottle - How I Love Thee

I didn't realize how much I needed a HWB (Hot Water Bottle) until my aunt blogged about them. I read the responses on Ravelry about all the people who couldn't get through a winter without one to cozy up to. I found mine for about $14 at RiteAid. It's nice to have a cover on the HWB since the outside gets pretty hot if you use HOT water (which I do).

I made a little sweater for it using this pattern. I knit it flat even though the pattern calls for knitting in the round. I used 100% cotton, worsted weight yarn. The color is oatmeal.
I added 2 buttons that I didn't know I had in my sewing box. They look pretty old and I wish I could remember where I got them.
I love my HWB! I lay it on my freezing cold toes while I knit, it warms my bed up before I climb in at night, and it keeps my fingers warm during a knitting break. The only problem is the cover I knit is too thick. The worsted weight yarn is thick enough that it doesn't let enough heat through. I'm using a pillow case as a cover right now.
My aunt created a wonderful cover for her HWB and I think I'll try knitting one soon with a lighter weight yarn.
I need a name for my HWB though. Any suggestions?