I honestly had to look into this, because it felt way over the top. But they actually do exist.

Dry ice vending machines are in stores, so that frozen goods won't melt on the way home.

As for the natural gas vending machine, those were directly hooked to a stove. Putting in coins and spinning the crank made it dispense gas for 10 minutes. But there's also seemingly no information on these on the english side of the internet.