How can food become contaminated with food poisoning bacteria?
Microbes are killed by heat. If food is heated to an internal temperature above 160F (78C), even for a few seconds, this is enough to kill most bacteria, viruses, or parasites. Toxins produced by bacteria vary in their sensitivity to heat. For instance, the toxin that causes botulism is inactivated by boiling, whereas the staphylococcal toxin is not.