Heat waves are a problem, no doubt, but you don’t solve it only thinking to big cities, like for pollution.

No, like the OP The Guardian article, I was talking about larger cities which have decent public transport. They are also hotter than their surroundings which makes relief more important.

Though specifically ozone is also problem in suburbia; it is formed there during the day by photochemical smog, but decomposes way slower than in the direct city areas.