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.
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.
Floors, walls, ceilings, lighting, ventilation, or garbage areas needed repair or cleaning. These are usually less urgent than food-handling problems but still need to be fixed.