Final answer:
To prepare a food warmer, fill it with water before turning it on and ensure it is set to the correct temperature for safe and even heating of the food. Use a thermometer to check that the food reaches a safe temperature.
Step-by-step explanation:
When preparing a rectangular food warmer for use, it is important to follow specific safety and operational guidelines to ensure food is heated properly and to avoid potential hazards. The correct statement describing the preparation of a food warmer for use would likely be to fill the warmer with water before turning it on. This ensures that there is a medium to transfer heat evenly and reduces the risk of overheating or damaging the warmer. Moreover, setting the warmer to the correct temperature rather than the maximum and ensuring it is clean and free from contaminants are also important steps.
To ensure the safety of the food, once it is in the food warmer, it is always advisable to use a thermometer to confirm that food reaches a high enough temperature to kill any bacteria it may contain, as mentioned in Figure 4.7.7.