Enlarge / People and their pets rest at the Oregon Convention Center cooling station in Portland as the city is hit with extreme temperatures caused by a heat dome on June 28, 2021 (credit: Kathryn Elsesser / AFP via Getty Images)

Northwest Oregon had never seen anything like it. Over the course of three days in June 2021, Multnomah County—the state’s most populous county, which rests in the swayback along Oregon’s northern border—recorded highs of 108°, 112°, and 116° Fahrenheit.

Temperatures were so hot that the metal on cable cars melted and the asphalt on roadways buckled. Nearly half the homes in the county lacked cooling systems because of Oregon’s typically gentle summers, where average highs top out at 81°. Sixty-nine people perished from heat stroke, most of them in their homes.

When scientific studies showed that the extreme temperatures were caused by heat domes, which experts say are influenced by climate change, county officials didn’t just chalk it up to a random weather occurrence. They started researching the large fossil fuel companies whose emissions are driving the climate crisis—including ExxonMobil, Shell, and Chevron—and sued them.