Abstract
Extreme temperatures are associated with higher overall mortality at the population level, but some individuals are more vulnerable than others. Here, we investigate how extreme temperatures affect mortality and how race stratifies this relationship in the United States. We use highly granular administrative and census data on monthly mortality in over 3,000 counties from 1993 to 2005, and link them to precise meteorological information. We find that extreme temperatures increase mortality risk, and that the extent of this increase varies between racial groups. For example, an extra hot day increases the monthly mortality rate of Blacks and Others by 6.3 and 11.3 per 1,000, respectively, but by just 2.4 per 1,000 among Whites. Conversely, of these groups, Blacks are the least vulnerable on cold days. Moreover, we simulate the number of additional deaths that would have occurred in the study period if temperatures had increased to those projected for the middle of the 21st century. Our findings highlight disparities in mortality risks under these projected higher temperatures. In particular, we show that excess mortality due to higher temperatures is six times higher among Blacks than it is among Whites. Thus, climate change could exacerbate existing racial inequalities in deaths related to extreme temperatures.