My dad has pretty bad neuropathy in his feet. So when he's confined to a bed for chemo or such, his feet feel like ice cubes. One sheet and two blankets covering a pair of socks weren't enough to halt it. Hey, I know what to do. Back in the day, we'd need to keep animals warm post surgery. Normally, we'd use fancy water circulating pads. But at times, I'd be doing procedures off-site at various academic labs that didn't have fancy equipment. I'd use a glove filled with warm tap water. So long as you tie the knot properly, it works pretty well. You never know when mice technology might apply to humans.