According to the US Department of Agriculture, hot foods must be cooled down to _________ after four hours.

The correct answer is that hot foods must be cooled down to 41 degrees Fahrenheit after four hours as per the guidelines set by the US Department of Agriculture. This temperature is critical because it helps to ensure food safety by reducing the risk of bacterial growth. When hot foods are cooked, they can reach temperatures that are conducive to the growth of harmful pathogens. By cooling them down to 41 degrees within a specified time frame, food establishments can minimize the time food spends in the danger zone, which is typically between 41 degrees and 135 degrees Fahrenheit. This guideline is part of the Hazard Analysis and Critical Control Points (HACCP) principles that aim to protect public health by controlling food safety issues.