Besides "milk men", there were "ice men" who would deliver ice to homes. [0] Demand for ice delivery turned into a major exterior feature of early 20th century homes, and you can still find small ice doors mysteriously adorning the Victorians of SF.
The first time I ever heard about the ice trade [0] and the iceman occupation was from the movie "Frozen". One of the main characters in the movie is an ice harvester by trade.
[0] https://en.wikipedia.org/wiki/Iceman_(occupation)