What should be done with food left out overnight?

Food left out overnight should be discarded to prevent the risk of foodborne illness because harmful bacteria can multiply rapidly at room temperature. The USDA advises that perishable foods that have been left out for more than two hours should not be consumed, as they can become unsafe to eat. This is particularly true for foods like meat, dairy, and cooked grains, which can provide an environment conducive to bacterial growth.

Refrigerating food that has been left out does not guarantee safety, as some bacteria can produce toxins that are not destroyed by refrigeration or cooking. Similarly, using it for cooking the next day or sealing and freezing it does not eliminate the risk that may have developed during the time it was left out. It's always safer to discard food that has been outside of safe temperature control for too long. By discarding it, you help ensure that you and others do not experience the negative health effects associated with foodborne illnesses.