Potato salad is one of the most popular dishes at picnics and parties. But it can also carry germs like Shigella and Salmonella – not exactly what you want to serve your guests! If cooked potatoes are not cooled down properly, germs can grow in them for extended periods of time. Couple these improperly cooled potatoes with mayo or oil, and you have a perfect breeding ground for germs to go nuts in before you put it all into your stomach.
Salmonella poisoning can cause vomiting, diarrhea (including bloody diarrhea), and fever. Shigella symptoms are usually diarrhea, cramping, abdominal pain, chills, feeling "out of sorts," headache, and fever. These are not the memories you want to have of that picnic.