Food was not kept cold enough, hot enough, cooled fast enough, or cooked or reheated to the right temperature. Bacteria grow quickly in the "danger zone" between 41°F and 135°F, which makes this one of the most important food-safety checks.
Potential food contamination prevented during delivery, preparation, storage, display
In plain English
Food was stored or handled in a way that could let germs or other material get into it, such as raw meat stored above ready-to-eat food or uncovered food. Cross-contamination is a common cause of foodborne illness.