It’s always a shame to be forced to throw out food and after forgetting the pizza on the counter overnight, you may assume that you have to toss it out. However, let’s allow science to way in on this question before you toss it in the trash bin!
Unfortunately, the temperature that your pizza will be sitting at overnight will be in what the USDA refers to as “The Danger Zone”. This danger zone is temperatures from 40-140 degrees Fahrenheit and is a range of temperatures that acts as a perfect environment for bacteria to grow.
The USDA also states that after two hours of sitting out at room temperature the food should be thrown out as bacteria will have formed within that time. There’s even a type of bacteria called “staphylococcus aureus” that is resistant to heat so reheating isn’t a saving grace!