Ship it cold. Keep the chocolate refrigerated until the time you need to pack. This will preserve the cooling energy of your cold packs instead of using it to make room-temperature chocolates cold.
Use cold packs. The size and amount of cold packs you’d need will be dependent on the amount of chocolate in the package, transit time and heat through travel. Usually, a small box (9 X 6.5 X 4 in) might only need one 2-4oz packet. Place the cold pack in a Ziploc bag or wrap it in some newspaper to ensure it doesn’t sweat on your package.
Choose a shipping box that is at least 2 to 3 times the size of the chocolates you are sending. Space allows for packing materials as well as keeping heat farther away from the chocolate in your package. Before placing the items inside, tape all the box seams to keep as much of the cold air in.
When ready to pack, use Mylar bubble wrap (silver-colored) to wrap around the cold chocolates. Mylar bubble wrap works great as heat deflection and insulator while keeping the product protected.
Stack box of chocolate with ice pack and wrap together with more Mylar. Seal with tape.
Add padding materials to the bottom of the box. Place chocolate and cold pack on top and fill the remaining empty spaces on the sides and top of the box to prevent any movement.
Close the package, seal with tape and address accordingly. Take to post office or shipping company and use the fastest method available.