Rice bags for heating

A number of years ago, my then 10dd made us all some rice bags. She's 18 now and those bags have lasted this long and seen a lot of use.

Here's what she did:
Cut some cotton or poly/cotton fabric to a 10"x 10" square (or make a 10" x20" rectangle)
She put the wrong sides together and sewed almost all the way around the bag, left an opening to turn the bag and be able to fill it.
She then filled it with about 2 cups of rice. Just regular, long-grain, uncooked rice.
She then sewed over the opening.

Whenever we need some heat - either on an aching body part or to warm a cold bed, we place the bag in the microwave and nuke if for 1-4 minutes. The amount of time depends on the wattage of your microwave and whether or not you're using this for a heating pad or wanting to warm a bed.

BE VERY CAREFUL using this with small children or elderly person! The bags can get very hot - depending on how long you heat it. They can be heated hot enough to cause a serious burn on a child or elderly person.