Mark, for some reason I'm thinking volatile oils need about 375*F.
I'm thinking those Sea cans that come in with cigars probably get pretty hot in the Carribean sun, and smokes don't seem to suffer?
Obviously the containers that are buried in the pile on probably don't get all that hot on the ship, but closed up and sitting in the shipyard they have to get pretty damned toasty.
Just thinking is all.