Apparatus for and methods of rethermalizing a package of refrigerated or frozen food are disclosed. In general, heating mechanisms are brought into conductive heat transfer contact with the package of food and operated for a duration of rethermalization time to rethermalize the package of food by heating the food to a rethermalized temperature, and then, if desired, to hold the rethermalized package of food at a desired holding temperature for a duration of holding time. The rethermalization time can be relatively short (e.g., thirty minutes or less), and the holding time can range from a very short period of time to a very long period of time (e.g., four, six, eight or more hours) without significant loss of food quality. Other features of the apparatus and methods are disclosed.