A Chillow® pillow turns an ordinary heat-trapping pillow into a cool comfort zone for deep, restful sleep! Tests show a cool pillow helps most people fall asleep more quickly and spend more time in the deepest sleep stage. Chillow® requires no refrigeration - just add water and place the thin, soft pad beneath pillowcase, or use alone for pillows that stay cool. Foam core with medical-grade valve and flocking. Each cooling pillow measures 21" long x 14 1/2" wide x 1/2" deep.