The LOTUS Mattresses are designed to help keep you cool as you fall asleep and remain cool through the night. The top layer of the LOTUS Mattress uses Arctic Ice open-air cell technology, which moves heat away from your body faster than traditional memory foam, providing you with a comfortable sleep without overheating. For additional help keeping cool through the night, we recommend: The LOTUS Arctic Ice Mattress Protector a water-resistant shell that uses PCM (phase-change-material) that cools on contact.  The LOTUS Canadian Birch Sheets, use birch fibres and a sateen weave which is cooling and breathable.