PHOENIX - A recent study found the majority of school lunches packed from home are not cold enough and this could make your child sick.
Researchers at the University of Texas at Austin tested hundreds of lunches packed from home and found 90-percent of them reached unsafe temperatures by lunchtime.
The recommended storage temperature is 40 degrees and under for cold foods.
David Ludwig with Maricopa County's Environmental Services Department showed how a cup of yogurt that was refrigerated reached nearly 60 degrees by lunchtime.
Ludwig gave advice to help keep your child's food safe.
First, choose well-insulated lunch boxes and make sure it's just big enough to fit your child's lunch.
Add more than one ice pack.
Partially freeze or refrigerate drinks before you put them in the lunch box.
Foods to avoid packing include undercooked meats, homemade dressings or sauces that have raw foods in them, and non-pasteurized cheeses and dairy products.
The best way to prevent bacteria growth is to wash your hands.
Ludwig says dirty hands are even more likely to make your child sick.