Final answer:
A food handler should recalibrate a thermometer after any changes in temperature.
Step-by-step explanation:
A food handler should recalibrate a thermometer after any changes in temperature. This is because temperature fluctuations can affect the accuracy of the thermometer.
For example, if the thermometer is exposed to extreme heat or cold, it may become less accurate. Therefore, it is important for food handlers to recalibrate their thermometers regularly to ensure accurate temperature readings.