Sleep comfortable knowing your mattress is protected. This waterproof protector is powered by Reactex and developed to be 5x cooler than standard non-Reactex products. Pressure-activated cooling starts working in approximately 8 seconds. Heat is pulled away from the surface and the body to help maintain optimal sleep temperatures. Stored heat energy is released when not in use to prepare for the next night. This mattress protector features a 230-thread count polyester/nylon blended fabric that can be felt through most sheets. Whisper-quiet waterproof lining prevents liquids from getting into the mattress.