I haven't used heating pads, but I did wake up with a scare one night after accidentally leaving a heating blanket on high and woke up in sweat. I had done a lot of research and I found quite a few opinions on that at the time. What I found was that, just like taking a hot bath, you don't want to raise your body temp up past 100 degrees or so. Obviously, a large blanket covering your body could do so. There were also docs who had warned of the dangers of the radiation that comes from heating pads and blankets. Apparently some give off more than others. Your back might be a safer place to protect from potential radiation, but as many readers suggested, I certainly wouldn't use it near your belly. If this is a potential concern, you may want to look into more natural remedies, such as a rice heating pad. If you're the 'green' type or are interested in more information, check this out: https://tipnut.com/make-your-own-microwave-heating-pad/