Tuna sub sandwich in rustic baguette with avocado, olives and sprouts

Heading outdoors for a picnic meal is an enjoyable rite of summer for many people. Instead of feasting on cold sandwiches, spend some time cooking something warm to serve at your next picnic. Your picnic will be a memorable feast when you serve warm and delicious food. Keep food warm for a picnic by using a standard cooler. Coolers are suitable for not only keeping foods cold but keeping foods warm as well.

Prepare the warm foods as close to the time of the picnic as possible. Alternatively, reheat the foods just prior to leaving for the picnic.

Wrap the warm food completely in aluminum foil.

Knead the gel inside a large hot pack with your hands for three or four seconds and place it in the microwave oven.

Microwave a large hot pack for up to 30 seconds. Remove the hot pack from the oven and knead the gel inside the hot pack again. Microwave the hot pack for additional 10-second intervals until the hot pack is sufficiently hot on all sides.

Place the hot pack on top of the hot food wrapped in aluminum foil.

Wrap the hot pack and the hot food securely in a large towel.

Place the wrapped food inside the cooler. If there is excess empty space inside the cooler, fill it with rolled-up towels to help trap the heat next to the hot foods and prevent it from dissipating.

Close the cooler and keep it closed until you are ready to serve the foods. Serve the foods within one hour for maximum food safety.