Our stainless steel boxes are not insulated.    If you want your foods to stay cold until lunchtime, the best thing to do is to pack the refrigerated foods the night before and chill the entire lunchbox (without the magnets on it) overnight in the refrigerator.  In the morning add the dry foods to the lunchbox.  Wipe any condensation from the lid and apply the dry magnets to the top of it.   Insert the lunchbox inside the bag with the ice pack and you are set to go.  The length of time that the lunchbox will stay cold is dependent on many factors such as what temperature it started out at, what temp it is being stored at, what type of ice pack you use, etc.  We have tested our ice pack in combination with our lunchbox and Carry Bag on a typical school day.  By pre-cooling the PlanetBox in the refrigerator overnight and then placing it inside the Carry Bag with the ice pack in the morning, a substantial lowering of temperature can be maintained.The exact temperature maintained throughout the day will depend on the ambient temperature the PlanetBox is stored at during the morning, exposure to direct sunlight or shade and the number of times the lunchbox is opened throughout the morning.In our tests, a consistent 40° F temperature was maintained inside the lunchbox while the exterior temperature was 75° F through the morning hours. According to the USDA, 40° F is a safe temperature to store perishable foods.If a significantly higher exterior (ambient) temperature is anticipated then we would suggest using two ice packs, one placed below the lunchbox and one above it to sandwich the PlanetBox in a blanket of cold throughout the morning. Please note that the ice pack can keep foods cool for as long as it remains frozen. To truly keep perishable foods from spoiling for long periods, store them in a refrigerator.