Doesn't stay hot for more than a few minutes [SEP] It's a rediculous price when you consider it doesn't work as well as rice in a sock works! I put rice in a baggie and then in a clean sock, it stayed hot for the 10 to 15 minute doctor recommended time frame. I thought this would be more convenient but it only stays hot a few minutes so you would have to reheat several times. It was a waste of money.