It's easy to deal with ants and other little picnic pests you can see; it's tougher to avoid the invisible organisms that can make you sick. Here are some guidelines for packing and transporting picnic foods safely:
The bugs that cause food poisoning thrive at temperatures between 40 degrees and 140 degrees F. Don't leave prepared foods in that danger zone more than two hours. When the outdoor temperature rises above 90 degrees F, the time limit is one hour. Discard any leftovers.
Wait until just before leaving home to pack chilled foods in an insulated cooler, and make sure you have plenty of ice or ice packs to surround them.
Take two coolers -- one for drinks, the other for perishable foods. That way, warm air won't reach the perishables each time someone reaches for a beverage.
In hot weather, keep the cooler in the air-conditioned passenger compartment of the car, not in the trunk. At the picnic, set the cooler in the shade.
Wash your hands before and after handling food. Soap and hot water are ideal; bring along a jug of water, a bar of soap, and paper towels, in case none are available at the picnic site. Disposable moist towelettes are an easy-to-carry alternative.
Wrap uncooked chicken and meats in separate tightly sealed bags or containers, and put them in the bottom of the cooler. Cook them within one hour of leaving home.
When grilling, use a meat thermometer to be sure meats and poultry reach a safe temperature. Cook chicken breasts to 170 degrees F; other poultry to 180 degrees F; beef, lamb, and veal steaks and roasts to 145 degrees F for medium-rare and 160 degrees F for well done.