EL PASO, Texas -- Fourth of July is this weekend and doctors said they tend to see about 20 or more cases of food poisoning in the emergency room. That's why food safety is of great concern especially this weekend.

Ants aren't the only little creatures that can spoil a summer picnic, food-borne bacteria from improperly handled, prepared or stored foods is another.

"I wash my foods, my vegetables and then when I have to refrigerate things I put them in the refrigerator and cover them up,” said Cindy Renteria, a mother of three.

Renteria is well aware of the illnesses associated with food poisoning. Leaving salads without appropriate refrigeration and not washing your hands properly are just some of the problems doctors say will lead to several cases of food poisoning.

Food safety experts said the key guidelines to follow for better picnic food safety are: clean, separate, cook and chill. The foods you need to be extra careful with are meat, chicken, and salads with eggs, mayonnaise and dressings, leaving those foods out too long causes an instant magnet for bacteria. Also, never let food sit out for more than hour in temperatures above 90 degrees. "I try not to leave them out but if I have to, maybe an hour, two hours,” said Renteria.

Experts say the clock is also ticking for food stored in the cooler, there's usually a two-hour maximum window for safely consuming food after the ice in the cooler is melted. It’s recommended to keep hot foods at 140 degrees or higher until served and cooking pork and hamburgers at 160 degree temperatures. Some of the symptoms of food poisoning include a fever or headache, stomach cramps and vomiting. Doctors said it only takes about 4 to 6 hours for the symptoms to kick in but it can leave you ill for 3 days or more.