I have been using the "Well Patch Heat warming patches". I can't believe how neat they are. They are for stiff aching muscles/joints. Somehow these patches stay warm/hot for several hours (up to 8 hrs) There are no chemicals like menthol etc. I have a terrible problem with knots, aching and stiffness in the right shoulder blade area, neck and shoulders. I put the patch on earlier today and it is still hot and my muscles are nice and soft. It feels great. This is the first time I tried these and I hope they will help me get back to work this week!!! I bought these at Rite Aid drug store. They are not prescription.