The threat of food-borne illnesses heats up along with temperatures in the summer months, so we turned to Marianne Gravely, spokesperson for the USDA Food Safety and Inspection Service in Washington, D.C., for the lowdown on keeping camp lunches fresh.

Follow this plan:

1. Put an insulated lunch bag in the fridge the night before so it starts out cold.

2. Freeze your child’s drink the night before, and place it at the bottom of the bag as one of two cold sources.

3. Prepare any foods that need to be kept cold the night before, and chill. When assembling the bag, place them right above the frozen drink.

4. Add a second cold source, like an ice pack, on top of the perishable foods.

5. Add room-temperature foods, like non-perishable snacks, to the top.