To determine the best cooling pillows, we sent 28 of the most popular options to real-world testers who slept on them for a minimum of seven consecutive nights (usually more), and evaluated them based on their quality, airflow, comfort, durability, and value. For expert advice, we consulted Dr. Peter Polos, MD, PhD, FCCP, FAASM, sleep medicine specialist and sleep expert for Sleep Number. Polos says that your pillow “can also have a physiological impact on our sleep quality—meaning that we might wake up more often throughout the night or not spend as much time in deeper stages of sleep that are needed to help us feel energized and refreshed the next day....