How about this (a true story): In Minnesota (USA), refrigerated trucks have to be heated in the Winter. Freezer trucks do not.
My company was located about 70 miles South of our supplier in Minneapolis. We ordered lots of media for culturing bacteria. That media needed to be "refrigerated," but it could not be frozen because of the agar. The biggest cause of QC failure was frozen media Then, the supplier discovered the need to keep his trucks above the outside temperature.
I think the diesel was a joke.
John
BTW, My daughter still lives in the forsaken place. It went below -26°F last week, the predicted low was -28°, so they were happy. People who still live there can tell the temperature by the tone that snow squeaks when you step on it.