by Craftbits (shellie wilson)
What you need
1 odd sock
2 cups of rice or wheat
Take the old sock, or new sock and fill it with the rice.
Leave enough room to tie a knot in the top of the sock. If you are using a smaller sock then use a rubber band.
This small heat pack can be used in pet beds under their blanket. Heat in the microwave for 1 1/2 mins on high.