Planning a picnic this weekend? A few simple precautions can protect you and your family from spoiled food and spoiled fun.

Dietitian Dianna Koenning of WakeMed says preventing food-borne illness starts with preparation.

"We all love melon at this time of year, but most people don't think about taking time to scrub the outsides of melons," she said. "But they do harbor contaminants fairly well, so use a scrub brush."

Transporting meats frozen is a good way to ensure that they stay fresh and bacteria free, but be sure that you cook them thoroughly once you reach your destination.

"A meat thermometer can help you make sure that the item is cooked all the way through," said Koenning. "And you're aiming for above 140 degrees for some meats, some as high as 165 degrees."

Mayonnaise-based salads aren't the danger that you may think they are, said Koenning. The real culprit is protein.

"The mayonnaise is actually acidic enough that it isn't the big risk factor, it's the protein," she said. "You want to keep mayonnaise-based salads cold, but don't worry as much about the potato salad as about the chicken salad."

And finally, when the cooler is packed for your trip to the lake, the beach or even grandma's house, put it up front with the passengers, not in the trunk.

"If you're traveling longer than 45 minutes in the car, you're looking at temperatures as high as 150 degrees in the trunk," said Koenning. "That's just the temperature that bacteria like."

Click on the video link above to hear Koenning's tips. Here are some more good ideas for keeping food safe:

• Pack drinks separately from food items. Frequent opening of the cooler can allow heat to get in, so keep foods as cold as possible until serving.
• Don't leave food out for long periods. If you're outside, don't leave any food, especially food with protein sitting out for more than an hour. If inside, aim for no longer than two hours before returning the food to the refrigerator or cooler.
• Pack meats at the bottom of the cooler to avoid dripping any juice onto other food.
• Pack foods that don't need as much cooling, like peanut butter sandwiches, crackers, nuts, or fruits like grapes and apples.
• Never use the same knife on meats and other foods unless you clean it with soap and water or an antibacterial cleaner between uses. The same goes for cutting boards.
• Keep fresh water close by your picnic area for cleaning.
• Don't try to keep leftovers from your picnic unless they've been kept on ice. "If the ice is melted, throw out the food," said Koenning.

Find out more about signs of and treatment for food poisoning.