A deadly heat wave in Pakistan has resulted in hundreds dead and follows the thousands killed in neighboring India this past spring during unusually high temperatures.

But mass mortality heat waves are hardly confined to poorer parts of the world: In 2003, the hottest European summer in half a millennium resulted in tens of thousands of health-related deaths. This summer also marks the 20th anniversary of the 1995 Chicago heat wave, in which over 700 died.

Eric Klinenberg’s 2002 book Heat Wave: A Social Autopsy of Disaster in Chicago analyzed that heat wave from a sociological perspective. Klinenberg mapped heat-related deaths to segregated, poor, and high-crime areas, where isolated and elderly African Americans were more likely to die than anyone else in the city.

Klinenberg’s findings were previewed in this earlier article published in Theory and Society. His title here is telling: “Denaturalizing Disaster” goes beyond “nature” to look at the society that natural disasters impact. The effects of poverty and vastly unequal distribution of resources (from income to social capital) are more important than the temperature.

Klinenberg argued that the “entrenched logic of social and spatial division that governs the metropolis” was the reason behind the unprecedentedly high mortality rate that summer. In other words, the real killer wasn’t the heat, but “the institutional and social mechanisms upon which extreme forms of American insecurity are built.”

Or, as the authors of another Chicago heat wave study, in the American Sociological Review, put it, “Disaster makes visible the social distribution of vulnerability.” With more extreme heat waves, floods, and, yes, snowfall (a warmer, wetter atmosphere produces more precipitation in all forms) expected because of global warming’s radical climate change, these are vital lessons to learn.