Nature’s Sleep Emerald Gel Mattress. Finally! A Mattress for Stomach Sleepers! The Emerald Mattress was born with a unique layered design to create an elevator effect, allowing the Gel Memory Foam to lower itself or rise up, based on a sleeper’s weight. The adjustments of the gel memory foam cradles the sleeper’s stomach and hips while reducing stress on the spine and air passageways. The Gel spheres infused in the memory foam reduces the sleep surface’s temperature by capturing excess heat and releasing it away creating a cool pleasant environment. The Emerald is great for all sleep types and is the perfect balance of comfort and support.