The Best Mattress From Every Top Brand, According To Online Reviews: "The highest ratings on Brooklyn Bedding's site come predominantly from side sleepers. The top two layers of the mattress are made with the company's proprietary TitanCool technology. It's a phase change material that liquifies when it heats up over 91 degrees, then shifts back once it cools down. Checking the mattress out in person, it is indeed cool to the touch. Whenever I'd shift positions, there was always an ice-cold spot to move to."