For example, liquid foods like soup kept in a hot slow cooker (149°F or 65°C) may last only a few hours before contamination, but fresh meats like beef and lamb that are promptly frozen (-2°C) can last up to a year. The geographical location can also be a factor if it is in close proximity to wildlife. Animals like rodents and insects can infiltrate a container or prep area if left unattended. Any food that has been stored while in an exposed environment should be carefully inspected before consuming, especially if it was at risk of being in contact with animals. Consider all forms of contamination when deciding if a food is safe or unsafe, as some forms or contamination will not leave any apparent signs. Bacteria may not be visible to the naked eye, debris (physical contamination) may be underneath the surface of a food, and chemicals may be clear or tasteless; the contaminated food may not change in smell, texture, appearance, or taste, and could still be contaminated. Any foods deemed contaminated should be disposed of immediately, and any surrounding food should be checked for additional contamination.