Leaving food too long in the temperature "danger zone" causes foodborne bacteria to grow to levels that can cause illness.
Leaving food out too long at room temperature can cause bacteria (such as Staphylococcus aureus, Salmonella Enteritidis, Escherichia coli O157:H7, and Campylobacter) to grow to dangerous levels that can cause illness.
Bacteria grow most rapidly in the range of temperatures between 40 °F and 140 °F, doubling in number in as little as 20 minutes. This range of temperatures is often called the “Danger Zone.”
