Hot air is useful.
A few decades ago I was going over a radar, sonar, stereo and autopilot install on a little 40' class boat.
Three young Doctors chipped in and bought it new and bare.
While talking, a 140' vessel was slowly moving down the Intercostal Waterway.
I waved to the Captain and he tooted the air horns in response.
The Docs asked if I knew the owner, and I replied, yes, but that's the Captain.
How does anyone afford a yacht like that, was their question.
The owner is a lawyer, was my reply.
What type of law does he practice, was their next question.
Medical malpractice, was my reply.
When they recovered from my joke, I said, the owner made his fortune buy bringing an old invention back on the market......
the hot air popcorn popper.
Fun days at the office.