Can prolonged use of an electric heating pad cause internal damage, particularly to the kidneys? I have been using an electric heating pad for chronic back pain nightly for 2 years+ 2-4hours at 113f-130f. I am concerned about possible internal damage, es

You . You won't hurt your kidneys but you can sure burn the skin on your back! ouch! i ask my patients with low back pain to use hot water bottles because they naturally cool off and you can't fall asleep and get burned.
It's . It's very unlikely that you would do internal damage, but you certainly could injure yourself more superficially. Skin burns from heating pads are quite common, and even have a name for them: erythema id agne. Be careful about the heat intensity you use. Warmer temperatures are probably not going to be that more effective.