Will be.
Generally, warmer pad packaging will be marked with a clear date of production, shelf life, etc., generally warmer pad shelf life is about three years, but because the manufacturer is different, warmer pad shelf life will be different.
And incorrect storage may also shorten the shelf life of a warmer pad, such as stored in a humid environment and so on. It is recommended to store it in a dry and cool place during the shelf life of a warmer pad while avoiding direct sunlight.