Organ harvesting.
Pallets are sealed. Container floor is oddly sealed. Container fits in airliner cargo space.
Human parts must be delivered same day.
Pallets aren't sealed, they are shrink wrapped. Human body parts are shipped in styrofoam containers or better to keep them cool.
There nothing unusual about this cargo container if it is a refrigerated container. The floor is not sealed, it has drain channels for washing out like most refrigerated container's do. The walls are lined to contain the insulation. I used to run a large Food Bank and we'd see many of these refrigerated Land and Sea boxes.
They do NOT fit in an airliner cargo space unless the nose or tail of the plane is specially designed to swing away or up to allow a full sized cargo container to be put in. . . and even then, they would be very awkward to insert. These are 8' X 8' X 20', 40, or 45' in standard sizes. Airliner pods have lopped off upper or lower corners to fit the curved spaces of a plane's cargo hold.
Truck loaded with Airliner Cargo Containers
Shipping of human body parts quickly would be far better handled by some organization such as FedEx to get them directly to a hospital that needs them. Doing a bulk transshipping just adds time as the pallet would need to be first assembled to be shipped, and then at the destination broken apart and each package reshipped to its final destination, all of which takes time, which such an organ need cannot bear.
My youngest daughter used to do blood runs for the local hospitals and Blood banks, running much needed blood rare blood types between source where they have what's needed and where a patient requires it. Using a styrofoam cooler and ice, she had a very short time to sometime make a run of a couple of hundred miles. They gave her a red light to put on her dashboard. . . but no siren. On some runs, she was allowed to stop and then run a red light if it was safe to do so. Blood has a much longer "shelf-life" than an organ.