Dan, I remember talking to Franck's about
it, they said it had to be refrigerated, and even charged us 25 bucks extra to keep it chilled while shipping. Some form of refrigeration, either ice or portable frig is needed for Trimix... Sorry to contradict you, Mr. 41 sir....
They have recently changed the requirements for shipment and storage at Franck's. Bimix isn't and Trimix is now cooled.