Our Tempflow Memory Foam mattresses patented Airflow Transfer System? allows the cooler air to flow in two directions, even when you are sleeping in the same position throughout the night. Cooler air will enter through the many small holes that go down through the surface of the memory foam and out through the convoluted channels on the firmer base foam. It also works in reverse, as air can enter through the side sand up through the surface holes. This unique system in our memory foam mattresses also allows a heat transfer as the warmer air radiates off the body and ventilates down through the holes and out the sides of the mattress. That is why we always keep a breathable fabric where the channels exit on the sides of the Tempflow memory foam mattress.