Sensacool 1500 MattressThe SensaCool 1,500 mattress is a medium firm pocket sprung, comfortable and supportive mattress with the added benefit of remaining cool at all times thanks to the Cool Blue foam used in combination with its pocket springs. The Blue Cool foam has all the comfort of memory foam, with the added benefit of its open cell construction, allowing it to remain cool and ventilated at all times. The SensaCool 1500 is built around a 1500 Pocket Spring unit.