Picnics can be a lot of fun. But improper handling of the food can mean trouble in the form of foodborne germs. Before you fill your cooler, review these tips for safer picnics.

Picnic tip No. 1: When you open the cooler, keep an eye on the clock.

“The general rule is to have food out only two hours,” says Kate Zeratsky, a Mayo Clinic registered dietitian nutritionist. “However, on a hot day – 90 (degrees Fahrneheit) and above — you want to limit the time that food is out in that hot weather to one hour.”

She adds, “You might even consider a bowl of ice. And, then, sit your food container in that ice. That can help maintain a cool temperature.”

Picnic tip No. 2: Pay special attention to proteins.

“Bacteria like protein,” says Zeratsky.

So keep meat cold until it hits the grill. Then, use a meat thermometer to make sure it’s cooked to a safe temperature. At least 160 degrees (degrees Fahrneheit) for ground meats and 165 (degrees Fahrneheit) for poultry.

Picnic tip No. 3: Shield your sweets, including the ones from Mother Nature.

“Fruit, with its natural sugars, is going to attract some bugs,” says Zeratsky. “So you might want to keep it covered.”

And picnic tip No. 4: Better to be safe than sorry.

“When in doubt, throw it out. You don’t want anyone to get sick.”