Interesting, thanks! In the U.S., I don't think we have hot water delivery at all, water comes to your buildings cold and is heated individually by water heaters in the buildings where it will be used. Although now I wonder what keeps our delivery pipes from freezing in the winter; maybe it just doesn't get cold enough here for them to, when the pipes are underground.

Video on the NYC steam system: https://www.nytimes.com/2014/10/10/nyregion/miles-of-steam-p...