Owners are advised to choose products with high heating speed and uniform heating area when purchasing. "Some heating pads have slow heating speeds, while others have different heating positions, which will affect the heating position. This will affect the heating effect." It is cheap to buy inferior heating pads. External heating pads are often directly installed on the cigarette lighter. Adding heating pads to the cigarette lighter is particularly easy to burn fuses; external appliances may affect the original circuit due to different power. It will cause short circuit of electric wires, damage electrical equipment and cause fire. In addition, according to the "Special Requirements for Electric Heating Blankets, Electric Heating Mats and Similar Flexible Heating Devices", electric heating blankets are calculated from the date of production, and the safe use life is 6 years, while the safe use life of electric heating pads is 3 years. In addition, the standard specifies that the product must be accompanied by a text or symbol for the useful life, and is clearly marked on the instruction manual in accordance with the relevant national standards. If not, consumers need to be vigilant.