Final answer:
A food handler should recalibrate a thermometer after dropping it on the floor to ensure the accuracy needed for food safety.
Step-by-step explanation:
A food handler should recalibrate a thermometer after dropping it on the floor. Dropping a thermometer can affect its accuracy, leading to incorrect temperature readings, which is critical in ensuring food safety. Thermometers are delicate instruments and can easily become uncalibrated when subjected to physical shock. Although not mentioned in the references provided, it is a well-known standard in food safety protocols. Maintaining the correct calibration of a food thermometer is essential to make sure that food reaches a high enough temperature to kill any bacteria it contains, ensuring it is safe to eat. Other situations, like leaving it in a hot oven or completing a shift, while important to note, are not typically associated with the immediate need to recalibrate a thermometer.