Packing your cooler should begin the day before you plan to use it. If yours has been sitting in a hot attic or garage, bring it into the house — so that it can cool down before use. To keep food the coldest — and safest — load it straight from the fridge into your cooler just before leaving the house. Remember to pack items in reverse order of when you’re going to use them. This way, the foods you plan to eat last will still be cold when you serve them. A few exceptions to this rule are raw meat, poultry and fish. Because these items’ juices can drip onto other items, load them first and on the bottom of the cooler. Packing these items frozen may also help to keep your cooler cold. To lock in cold air, remember to keep the lid closed as much as possible. According to Home Food Safety, when you remove food, don’t let it sit out for more than two hours — and one hour on hot days above 90°F.
