Don’t leave baked potatoes in the foil they were baked in, especially at room temperature.
Potatoes can harbor Clostridium botulinum, a bacterium naturally found in soil that causes botulism.
Though cooking kills the bacteria, their spores—which produce a deadly toxin—can survive, germinate and multiply in the oxygen-poor environment within the foil.
Scrub potatoes before cooking. Serve them right away, and store leftovers immediately, unwrapped, in the refrigerator.