I had a history prof in college tell me about his time that he spent in Burma during WWII. He said it was hotter than hell and nobody could really enjoy drinking their beer at 100+ degrees, so they would take everybody’s beer and load it up into a bomber, take it up to 20,000’ or so for an hour and bring it back down. Voila! Cold beer. He said he often wondered what it cost Uncle Sam to refrigerate their beer. I thought it was a great little story.
When my dad was in the service with the PR Air National Guard, anytime they deployed anywhere, one of the last things to be loaded on the cargo planes they rode was several cases of beer, placed on the C-130 cargo ramp.
He says by the time they reached 20,000 feet, the beer was nice and frosty...this, of course, from the days when the PR ANG would allow them to get plastered on board cargo planes...the good old times.