I made a bunch of these microwave rice hot packs so we can be toasty anytime of year. Heating pads or hot water bottles have been around for centuries and for a good reason; they are soothing and therapeutic with a myriad of health uses.
For the ones shown, I simply cut some fabric swatches (one was even an old hawaiian shirt of my hubby’s that he didn’t want anymore) into various sizes, rectangle, square and a heart. I sewed them up like you would a pillowcase; by turning the fabric inside out, sewing 3 sides and leaving one open to put in the rice. Then, I turned it back the right side out and filled it with rice (you could also use flax which hold heat well, but don’t use buckwheat hulls as they suck for heating purposes!). I also added a few drops of lavender essential oil to the rice-then I sewed the final side shut.
Don’t burn them in the microwave-they will burn if you don’t watch them. We usually heat for 30 seconds at a time, flipping them and it takes about 3 minutes for the heat consistency that I like.