More than 100 million people in the U.S. will live in areas exposed to heat indices of over 125°F by 2053 years and people of color will be disproportionately harmed, a new analysis by the First Street Foundation warns. Currently, 8 million people in the U.S. are exposed to heat indices of 125°F every year, but that number is expected to skyrocket to 107 million, including in the developing “Extreme Heat Belt” stretching from Brownsville, Tex., to Chicago, Ill.

In 30 years — the length of a typical home mortgage — close to two-thirds of Americans will experience at least three straight days with a heat index over 100°F, according to a Washington Post analysis of the group’s data, and some regions could see as many as 70 straight days with heat indices in triple digits. A number of historic and presentday racist policy decisions combine to put people of color at greater risk of extreme heat (and pollution) exposure.

Neighborhoods with large populations of color will suffer far more than whiter neighborhoods, an E&E News analysis of the data found. So-called “majority minority” ZIP codes will experience an average of 43 days of extreme heat by 2053, more than double the 19.5 days experienced by ZIP codes that are 90% white. (Washington Post $, E&E News, Axios, CBS, Gizmodo, NBC, The Guardian, USA Today, ABC, People, Fortune; Climate Signals background: Extreme heat and heatwaves)