Final answer:
Hot food being held with temperature control should be checked at least every 2 hours to ensure food safety.
Step-by-step explanation:
The temperature of hot food being held with temperature control should be checked at least every 2 hours. This is because bacteria multiply most rapidly between 4 and 60 degrees Celsius (40 and 140 degrees Fahrenheit). If hot food remains within this temperature range for more than two hours, it may become dangerous to eat due to rapid bacterial growth.