My two cents worth here :):) Go to your 'good food store' or whatever its called in your area. Buy RAW BUCKWHEAT GROATS.... buckwheat holds the heat better and longer, doesn't smell and lasts forever. If you get a wild hair for a certain scent (i.e. lavendar) the buckwheat will take the scent great. I make tons of these bags every winter. Can heat them in the microwave for 3-5 minutes and they are awesome.