Dreamstime_s_16788177 With food luminaries like Alice Waters calling for major reforms to American school lunches, sending kids to school with a packed lunch can ensure that they get a balanced, nutritious meal. Since 4 out of 5 kids don't get access to refrigeration, though, it's important that parents do everything they can to ensure that kids' food remains at a healthy temperature where bacteria can't grow. A recent study of more than 200 kids' sack lunches found that only 1.6 percent of perishable items packed by parents were in the safe temperature zone. How can you ensure your child's lunch stays safe?

First, check out the lunch box you're currently using. While insulated, soft-sided lunch bags provide a good base for temperature control, adding an ice pack to almost any container– from a traditional hard-sided box to a brown paper bag– is usually enough to keep food cooled at a proper temperature. As we all know, kids are prone to losing items, so you'll have to take your budget and your child's age and level of responsibility into account when choosing a container. If they're regularly tossing their paper bags at the end of lunchtime, will they be able to remember to take the reusable ice pack home every day? Or would it be better to conceal it in a reusable bag? If possible, you may want to keep a second lunchbox or bag and some additional ice packs on hand, in case the originals go AWOL at school.

Next, you'll have to decide what goes in the bag. The USDA recommends preparing cold salads and meat the night before, so they have time to chill thoroughly before going to school the next morning. One way of ensuring sandwiches stay cold is freezing them the night before, so they'll stay chilled all the way until lunch time. If your child's favorite concoction includes mayonnaise, lettuce, or tomatoes, though, keep them set aside in a sealed container in the fridge and add them in the morning– they don't freeze well.

When it comes to hot food, the USDA suggests using an insulated container to keep soups, stews, and chili hot through the morning. Before using the container, fill it with boiling water, let it stand for a few minutes, and then add piping-hot food. Hot food should always stay above 140 degrees, and most insulated containers can maintain this temperature for at least a few hours. If your child's school allows them to use a microwave to reheat their own food, instruct them to cover the food with plastic wrap or a microwave-safe top, which holds in moisture and ensures everything heats evenly. Food should be piping hot, without any cold spots.

Teaching kids about the risks of improperly handled food is also important. (This CDC page does a great job of detailing all the information above in a kid-friendly style.) If their cold pack thaws or they see any mold in their food, they shouldn't eat it. Keeping a small amount of money in each child's school-lunch account, if possible, can ensure they get fed if something goes wrong with a packed lunchbox. If all else fails, encourage children to speak to a teacher or administrator if something's wrong with their lunch, so alternate arrangements can be made. Kids need plenty of food energy to keep them focused in school and active at recess, so it's important that they don't miss a meal.

Looking for some ideas to add more healthy foods to kids' lunchboxes? We've compiled a ShopWell list of easy-to-pack, nutritious lunchtime snacks.