It's Tuesday and it's time for Bruce and Mark to relieve you of another culinary myth you've probably though was true since childhood. This time, it's that the mayonnaise in the egg salad/chicken salad/pasta salad at your family picnics is what what ends up making everyone sick. Sure those salads sat in the sun for an hour. But store-bought mayo is fairly acidic and doesn't go bad quite so fast. Chances are if everyone gets sick. it's from the chicken, the tuna, or other protein sitting in that mayonnaise. Those things have a much higher Ph and lower acid content which makes them prime candidates for turning bad in the sun. We're not saying there's any other answer rather than keep your food cold, that is under 40 degrees F or under 4 degrees C. But if you do get sick, it probably wasn't the mayonnaise that did it to you.