Coir is also called coconut fiber. Since rubberized coir mattresses are made with natural fiber treated with latex, they are firm, porous and breathable. Thus, they provide support to your entire body. With its porous nature, coir mattresses allow the passage of air in and out and this natural ventilation makes the surface cool for sleeping.People who have back pain could get some relief with the use of a coir mattress as it provides rigid support along the length of the spine and thus maintains the natural spine alignment.