Always Cool brand pillows use fabrics to cool the head. The designers of these pillows used a spiral-crimped polyester with loose texture, similar to thread. The pillow comes with a hypoallergenic cotton pillow cover for those who suffer from allergies. Everything about this pillow is washable. According to the Hammacher Schlemmer Institute, a non-profit organization that tests consumer products, these pillows were designed to help astronauts adapt to extreme temperature fluctuations while sleeping. The various brands of cool pillows are meant to be cool, but not cold. Cool pillows provide comfort, while cold pillows can be uncomfortable.
Cooling circulation pillows were developed in Japan. They release cool air from a motor in the center of the pillow. The designers used polyester to build the exterior of this pillow. The interior uses a variety of water-resistant materials, such as water-absorbent resin, urethane foam, non-woven polyester, and mold-proof agents.
Some cooling pillows use refrigerant gels. You can place the refrigerant pillow in the freezer or refrigerator. The refrigerant becomes cold, and then keeps the pillow cool for the owner's head. You should test the pillow to see if it is cool or cold. If it is cold, it will not feel good. Once the pillow has cooled sufficiently, you can can rest your head on it for comfort.
A person seeking cool comfort from a pillow can refrigerate the pillow before putting it under her head. This technique works for a limited time, and it can cool the head too fast, making the user uncomfortable. If you simply want a slightly cooler pillow, you can put a fan on the pillow to direct cool air toward it. Or you can simply flip the pillow occasionally to use the cooler side.