How long can chicken that has been cooked stay out? 

A good rule of thumb to follow when it comes to cooked chicken is that you should not let it stay out on your kitchen table or buffet for more

than two hours at a time unless it is maintained warm at a temperature of at least 140 degrees Fahrenheit.

It is recommended that you dispose of any cooked chicken that has been left out at room temperature for more than two hours.

The same rule applies to fully cooked chicken that is consumed in the open air, such as during a picnic or a barbeque.

However, after one hour, the chicken that has been cooked should not be consumed if the temperature either inside or outside is higher than 32.2 degrees Celsius. 

Why do we need two hours? 

It may come as a surprise to hear that bacteria that may cause sickness, such as Salmonella and E. coli, 

which are often found in chicken, reproduce rapidly between temperatures of 40 degrees Fahrenheit and 140 degrees Fahrenheit, also known as the Danger Zone.

According to the Food Safety and Inspection Service of the United States Department of Agriculture (USDA), the number of germs might really double every 20 minutes.

When translated literally, this means that millions of germs may already be present in the chicken after it has been cooked and allowed to hang out for many hours.