Journalist Jesse Winter ventured out with a thermometer during a heat wave last summer. The temperature differences between wealthy and poor neighbourhoods were staggering.
Community forests the size of a basketball court can make an outsized difference, providing shade, attracting plants and animals, and even storing a bit of carbon.
From Phoenix in the United States to Mumbai, India, and Paris, France, as cities try to combat pollution and improve air quality, urban forests are mushrooming.
