The sidewalls of this pillow are constructed with an integral 100% recycled green fibre fill which provides greater cushioning characteristics and enhanced durability during washing. The inner self-cooling mat is filled with a non-toxic gel and will be typically 5-10 degrees cooler than room temperature. When in use, the mat will maintain its cooling properties for approximately 1 hr depending upon the environment. To reset the mats cooling properties simply leave it unused for 1 hr and there is no need to freeze or refrigerate it.