This invention relates to a self-heating container for heating beverages or food contained within the container. The self-heating container or can includes a cup containing active lime that is positioned underneath a thin plate and another cup filled with water. When a bottom cover of the self-heating container is pressed downwardly, sharp spikes above the water cup pierce a thin plate located between a chamber containing the water and the active lime and causes the water inside the cup to flow into the active lime which results in a chemical reaction that heats the contents of the can or container.