In 2003, as Paris sweltered through a heat wave that would go on to kill an estimated 15,000 people across France, one oasis of cooler air remained off limits: the city’s roughly 400 public parks. They were temporarily closed due to the danger of falling tree limbs.
“That basically deprived people of the one small sliver of green space that they might have had in order to find a slightly cooler atmosphere,” says Richard C. Keller a professor of the history of medicine at the University of Wisconsin-Madison and author of Fatal Isolation: The Devastating Paris Heat Wave of 2003.