The present invention relates to a self-heating container for heating consumable items such as food and beverages. The container assembly includes a star-shaped inner container for holding heating media that produces an exothermic reaction, and an outer container for holding a consumable item such as food and beverages. The inner container includes a thermally conductive polymer composition, and the outer container includes a heat-insulating material. The thermally conductive polymer composition includes a base polymer matrix and filler material.