The age-old Memorial Day question is which comes first, the chicken or the ribs on the backyard barbecue grill?

The choice of chicken, ribs, burgers or steaks isn't the most important thing in your backyard cookout. Not the way Judy Harrison, a food safety expert with the University of Georgia Extension Service, sees it.

"Put safety first," Harrison said. "Safe food handling is always important. But during the summer grilling season, we need to be even more aware of food handling practices."

In the backyard or at a picnic site, people "may not always be as good at hand-washing and personal hygiene as they are in the kitchen," she said.

But keeping hands, dishes and utensils clean is just as important when grilling. Outdoor chefs aren't the only ones to thrive on toasty days. The bacteria that cause food-borne illnesses flourish, too.

"Nothing can spoil summer fun like a case of food-borne illness," Harrison said. Symptoms can range from diarrhea, vomiting, abdominal pain and fever to long-term health problems such as arthritic conditions, heart complications and central nervous system or kidney disorders. Some cases can kill.

Anyone can get sick from the backyard grill or whenever food is mishandled, Harrison said. Infants, young children, the elderly and pregnant women are especially susceptible to complications of food-borne illness. So are people whose immune systems are weakened by AIDS, liver disease or cancer treatment.

"Fortunately, food-borne illness is preventable," Harrison said. You just have to pay attention to food safety rules.

Start with clean hands, utensils, dishes and work surfaces. "If you're grilling away from home, take some disposable hand wipes along," she said.

Keep any meats refrigerated or in a cooler until the grill is hot, Harrison said. Marinate raw meat, fish and poultry in a glass dish in the refrigerator -- not on the counter.

Once you put it on the grill, cook meat and poultry thoroughly. "It's best to use a meat thermometer to check for doneness," she said.

Cook large cuts of beef like roasts to an internal temperature of at least 145 degrees Fahrenheit for medium rare, 160 for medium and 170 for well done. "Be aware that meat cooked to 145 degrees still carries some bacterial risk," she said. Cook whole poultry to 180 degrees.

Whatever you do, don't undercook hamburgers. "To be sure you destroy bacteria, cook meat patties to at least 160 degrees and ground poultry to 165 degrees," Harrison said. "No pink color should remain in the meat. The juices should run clear, with no evidence of blood."

Some outdoor chefs like to speed grilling time by partially precooking meat or poultry. That's OK if the food goes right from the microwave or range to the grill, she said. But interrupted cooking is risky business.

When it's done, never put grilled food back on the dish that held the raw meat or poultry. "If you put meat or poultry back onto plates with raw juices," she said, "you can put bacteria right back on the foods you just cooked."

Grilled food never tastes better than when it's hot, right off the grill. It's never safer, either.

"As with any food, don't eat grilled foods that have been left at room temperature for more than two hours," Harrison said. "If the food is outside on a hot day (85 or warmer) one hour is a safer rule."

Put properly handled leftovers promptly in the refrigerator or cooler. "Divide larger quantities into small, shallow containers so they can cool quickly," she said.

If you're picnicking and plan to return home within four or five hours, keep perishable leftovers on ice until you get there. But throw out any perishable food that was left out for more than an hour on a hot day.