This term Food Warmer is somewhat of a misnomer. Why do we make this statement? Generally food warmers do not heat up food, they are intended to keep food warm. If they do heat up food, they are referred to as a re-thermalizer. That said, the rule is hot to hot, or hot food going into the warmer to keep it warm. When making a selection of a Counter Food Warmer, one should pay attention to the wattage or kW, for the higher the wattage the faster recovery in terms of heat.