I transported milk from Puerto Rico to Washington, DC last January. We used regular foam coolers placed in cardboard boxes to give them more protection then used the shrink-wrap now available in many airports. We used 2 lbs of dry ice in each cooler (Burger King had allowed us to use their freezers to get things as cold as possible), and even though the milk got lost with baggage and deliverd 24 hours later, the milk was frozen solid. The airliners treat dry ice like a hazardous substance - only a cerain amount is allowed in each plane, so you need to let them know wht you´re taking and how much dry ice is in each box... I was told that the dry ice, when fumes are released, can put pets traveling in the baggage compartment in danger - which is why it is controlled. It is of course not explosive or dangerous... Jeanette Panchula, BSW, RN, IBCLC Puerto Rico [log in to unmask]