If it's cold weather and the power is out, but you have a gas water heater, fill up empty 2 liter pop bottles with hot water, one to hold on your lap and one between your feet. Top off with layers of blankets.

Small pop bottles filled with hot water can go in your coat pocket and you can probably put your hands in there, too.

Warm up your sittin spot or bed with them before you climb in, as long as you know they won't leak.

This is how I got through a bad ice storm with freezing temps and no power for a week.

Many GREAT tips in this thread. Thank you OP and all contributors.