This topic makes me smile and think of when I was young.
In 1980 I was employed at a Mercedes Benz dealer as an apprentice. One of my duty's was to perform pre-delivery inspections on new cars coming off of the transporters.
The dealership was in Pasadena, California, where on an extremely cold January night it might get down into the 40's.
In the glove box of every diesel car was a freeze plug looking "thingy" with a heating element and an electric cord attached to it. The first time I saw one I had no idea what it was. My mentor laughed and told me to pull it into my stall, drain the coolant into a clean container, pop out the easiest freeze plug to get to, install the block heater, and put the coolant back in. Then, roll up the cord and zip tie it securely somewhere out of the way...because it's never going to be unrolled.
Mercedes insisted we install them.
A few months later I went to Mercedes/Benz of North America training school. Next to me was a trainee from Fairbanks, Alaska. When talking about the block heater, he laughed. He said that they simply never turn the engine off...for months at a time. The cars also had a curtain dealer installed that you could work from the drivers seat that blocked air flow from the radiator.
Really!