Containers for food, and methods and systems for making and using the same. An exemplary container for food can include an insulated tray including one or more sub-units and one or more heat sink units configured to store the food and fit in the tray. An alternative container can include a container base and a receptacle fitting in the container base, the container base including one or more thermal function pieces therein for maintaining a temperature of the receptacle. An alternative container can include a serving base defining one or more slots for holding the food items, respectively, and a cover configured to cooperate with the serving base, wherein at least the serving base, or at least the cover, includes a thermal function piece, the thermal function piece including a phase-change material. An exemplary method for using the container includes treating the phase-change material to an initial temperature.

A self-heating or self-cooling system and method for providing instant cooling or heating to a product or a surrounding area. The system can include an outer container that is configured to slidably receive an inner container. A piercing member extends from a bottom wall of the outer container and is configured to pierce, break or rupture a sealed end of the inner container so that at least two separate liquids can mix to either create an exothermic reaction that produces heat or an endothermic that absorbs heat or has a cooling effect. The inner and outer containers can be lock in a closed position when the inner container is pushed into the outer container. A sealing arrangement is configured between an interior surface of the outer container and an exterior surface of the inner container to prevent leakage of fluid from the interior chamber of the outer container.

Containers for food, and methods and systems for making and using the same. An exemplary container for food can include an insulated tray including one or more sub-units and one or more heat sink units configured to store the food and fit in the tray. An alternative container can include a container base and a receptacle fitting in the container base, the container base including one or more thermal function pieces therein for maintaining a temperature of the receptacle. An alternative container can include a serving base defining one or more slots for holding the food items, respectively, and a cover configured to cooperate with the serving base, wherein at least the serving base, or at least the cover, includes a thermal function piece, the thermal function piece including a phase-change material. An exemplary method for using the container includes treating the phase-change material to an initial temperature.