Heating pads come in various forms, including electric, microwaveable, and chemical heat packs. Electric heating pads are among the most popular due to their consistent heat settings and quick heat-up times. Microwaveable heat pads, often filled with grains or herbs, provide a gentle and moist heat that can be especially comforting. Chemical heat packs offer portability and ease of use, making them great for on-the-go pain relief.