Serta's iComfort Quilted Hybrid Collection combines Cooling Specialty Foams with Premium Individually Wrapped Coils then topped with a more traditional quilted top, with cooling features like the Max Cold™ Cover and the UltraCold System™, assuring you sleep cooler. Every iComfort mattress includes exclusive Carbon Fiber Memory Foam. This system channels heat away from your body and provides exceptional strength for back and neck support. Featured in the 4000 series is the Air Support™ Foam, an exclusive air-cushion technology, that moves with your body and smartly contours around it to help alleviate aches and pains caused by pressure points. Additional pressure relief and cooling is achieved with Gel Memory Foam. This Medium Pillow Top Mattress is ideal for a side or back sleeper.