Final answer:
Hot food should be heated to 74 degrees Celsius before being put into a buffet table or hot-holding unit to prevent bacterial growth and ensure food safety.
Step-by-step explanation:
The proper temperature at which hot food should be heated before it is placed into a buffet table or hot-holding unit is 74 degrees Celsius (165°F). This temperature is hot enough to minimize the risk of foodborne bacteria and other pathogens growing to unsafe levels. It is important to adhere to this standard to ensure food safety and prevent potential foodborne illnesses.