Abstract: Fire retardant and heat resistant yarns and fabrics include a fabric or yarn comprised of oxidized polyacrylonitrile at least partially coated or encapsulated by a strengthening polymer material that helps the fabric or yarn shed liquids, gels, sparks, and molten metals. The polymer material includes one or more types of cured silicone polymer resin. A fluorochemical may be at least partially impregnated into the fabric or yarn prior to applying the strengthening polymer material in order to further enhance the shedding properties of the yarns or fabric. In one embodiment, the silicone polymer resin only coats or encapsulates the yarn, but does not form a continuous coating over the whole fabric, so that the treated fabric is still able to breath through pores and spaces between individual yarn strands that make up the fabric. The polymer material increases the strength, abrasion resistance, durability and shedding capability of the fire retardant heat resistant yarn or fabric.