More from the article ...

... As heatwaves intensify across Europe, most cities are reaching for a familiar fix of more air conditioning. But in 1990s Paris, planning began for a different kind of solution: one of the world's largest district cooling networks.

The system has 120kms (75-miles) of underground pipes distributing chilled water to museums, offices, hospitals, schools and other public buildings including the Louvre, the Grand Palais, and some luxury hotels and office districts. Instead of thousands of individual air-conditioning units, cooling is produced centrally and shared across the city like a utility.

The system circulates cold water through a network of pipes: cold river water from the Seine is pumped through one pipe, which runs right next to a secondary pipe carrying warm water from the city's buildings. A thin metal wall separates them and a heat exchanger allows the heat from the warm city water to enter the cold Seine water without the fluids ever touching. It is similar to holding a cup of hot tea in a bowl of cold water " the liquids don't touch, but the tea cools down. ...

@#2

Yeah, air-conditioning (called air-con, as opposed to a/c, there) is relatively rare in France, a lot of Europe for that matter.

On one business visit to Rotterdam, Netherlands, the four-star hotel I was staying in did not have air-conditioning. That week the temps hit the mid-90's.

... City plans to triple system of underground pipes that distribute chilled river water, reducing need for individual cooling units ...

Similar to Mew York City's utility distributing steam to buildings for heating during the winter