If you use a patch (mine is Fenayl, working well btw, but still have pain from 8 to 10 MOST days, but now have more 4 days._

Anyways,

If you use a patch and then put on a heat source the medicine escapes too fast and easily can KILL you. MANY ER nurses told me this, and the warning label too.

Just fyi. I use heat for my low back and legs sometimes.