Buy an insulated shipping box, preferably made from a thick polystyrene or urethane. Cheap Styrofoam containers break too easily. The shipping box should not be airtight, as it must be vented to allow the gas to escape as it changes phases.
Purchase 5 to 10 lbs. of dry ice for each 24 hour period the food needs to stay frozen. More dry ice is needed for containers larger than 15 qts. Use a dry ice directory on the Internet to find the nearest retailer. Pick up the dry ice as soon as possible before use since it will start changing phases from solid to gas immediately.
Pack the shipping box with the dry ice and frozen food. Handle dry ice with insulated gloves and avoid any contact with skin because it is capable of inflicting frostbite burns. Place dry ice primarily in the top of the package unless you are shipping a great deal of frozen food and you may want to put some of it at the bottom. Fill any empty space in the container with a shipping material like packing peanuts or newspaper to slow the sublimation of the dry ice.
Fill out paperwork properly for the courier you are using. The postal service, FedEx, and UPS all allow shipments with dry ice, but it is a potentially dangerous material so you may need to claim it and possibly attach a special label to the package.
Ship your package using the fastest available shipping rate. Overnight or express shipping is the best option, but be aware of possible shipping delays over weekends and holidays.
