Bests & Worsts Reviews from Amazon

I bought this heating pad to use in bed to help with sore muscles and cold feet. For the first few days I liked it a lot - it worked just the way I imagined it would. BUT - then I read the tag near the plug, and to my astonishment it said: "Never use the pad between yourself and chair, sofa, bed, or pillow." Say WHAT? That's what I bought it for - to set on my bed, add sore muscles or cold feet, top with sheet and blissfully fall asleep. But the tag says "Do not use while sleeping." So now my dilemma - do I use the pad for the purpose I bought it, or pay attention to the warnings? And where on this site should I have found this warning so I would have known not to buy it???