Memory foam mattresses are topped with a layer of visco-elastic memory foam. This moulds to the body easing pressure on joints, bones and muscles as your body sinks into the memory foam. Most memory foam options have a Reflex foam base which provides a firm and supportive base, this compliments the memory foam and helps to provide a balance of comfort and support. Furthermore, memory foam has hypo-allergenic properties protecting against bacteria whilst easing the symptoms of Asthma and allergies.