Pick a main dish based on beans, whole grains, or canned seafood or meat to avoid potentially hazardous bacterial growth, especially if the lunch box will not be refrigerated. High heat provides optimal bacteria growth conditions. Tasty main dishes for a lunch box on a hot summer day include cold pasta salad, unopened canned tuna packed with whole grain bread, and mustard or peanut butter baked oatmeal bars.

Tuck crisp, juicy fruits and vegetables into the lunch box to provide a handheld burst of refreshing moisture and flavor. Ultra-juicy fruits include watermelon, honeydew melon, cantaloupe, apples, berries and mangoes. Refreshing veggies include carrots, cucumbers, cherry tomatoes, romaine lettuce, bell peppers and sugar-snap peas. Pack ranch dressing for dipping, if you can keep it cool. Combine the vegetable aspect of the lunch with the main dish by packing a big veggie-rich salad with garbanzo beans or black beans.

Pack a beverage in the lunch box to encourage the lunch-eater to stay hydrated in the heat. While plain water is always a healthy choice, go for 100 percent fruit juice for a swig of tasty natural energy. Pack milk only if the lunch will be refrigerated or kept cool. Use an insulated beverage container for a cool drink.

Include a sweet surprise in the lunch box that won't make a mess. Skip anything that will melt or get sticky. Some hot summer day dessert possibilities include pudding, sugar cookies, cereal bars, fruit salad and yogurt tubes that you have frozen the night before. The yogurt will help keep other foods cool and thaw sufficiently by lunchtime.