Potato salad should be kept cold while serving if it is going to be out of the refrigerator for longer than 30 minutes. Cold food should be kept cold when serving. To safely serve this mayonnaise based salad at a barbecue, picnic or an outdoor get together fill a larger bowl than the bowl the salad is in with ice cubes. Place the salad bowl on top of the ice to keep the salad cold. Replenish the ice as needed.