Summer is a great time to eat al fresco, whether you're grilling or having a potluck -- or both. But besides the bugs, be sure you don't invite some other unwanted critters to your meal. We're talking about bacteria that can make you and your fellow picnicgoers sick. Bringing food outside to allow people to serve themselves is the first thing that might put diners at risk. Hot summer temperatures allow food's temperature to increase rapidly, making it more hospitable to germs. If you're partially cooking food on the stove or in the oven prior to grilling it, then be sure it goes straight from the kitchen to the hot grill -- don't leave it sitting around, allowing bacteria to grow. Meat, poultry, eggs and creamy salads are the biggest culprits when it comes to bacteria.