We believe that PVC cords can be used sufficiently if the temperature is expected to be low (up to about -10℃), and if there is no requirement for cord materials in the safty-standard, we use inexpensive PVC cords as the standard. When using in a special low temperature environment beyond expectations, we think that a cord made of a material with good low temperature characteristics, such as a cord made of rubber or polyurethane, is suitable.