In brief
Extreme heat waves in the United States, Europe and across the globe have added thousands of excess deaths in 2024. In Phoenix, Arizona, the Maricopa County government has combined cooling centers, 24‑hour access, air‑conditioning subsidies and the appointment of a dedicated heat officer to dramatically cut heat‑related fatalities. The county’s death toll fell from 645 in 2023 to 405 in 2025, a drop policymakers attribute to these measures. Experts argue that the model—coordinated public health outreach, infrastructure upgrades and systematized emergency response—could be replicated in cities that face rising temperatures, underscoring that heat is not just a health issue but a major urban and economic threat. Climate‑induced heat will intensify, so governments must plan for future extremes now, or risk increased losses.
By Ana Faguy
It has been a blisteringly hot summer for much of the US and Europe, with scientists warning that these extreme temperatures are becoming the new norm.
France logged over 2,000 excess deaths during a record‑breaking heatwave in late June, while England and Wales saw an estimated 2,700 heat‑related deaths since May. The UK’s independent assessments report at least 44 heat‑related fatalities in the US over the 4 July holiday weekend.
These crises highlight how rising temperatures blunt the natural cooling of nighttime, erasing the body’s buffer against heat stress, according to Yale researcher Jennifer Marlon.
Against this backdrop, Phoenix—one of the world’s hottest cities—has long been a pioneer in opposing heat deaths. Maricopa County first hired a heat officer in 2021, then built a comprehensive strategy that includes cooling centres, free air‑conditioning for low‑income residents and homeless people, and a programme that repairs or replaces residents’ air‑conditioning systems.
Over the last few years, these initiatives have paid off. After a peak of 645 heat‑related deaths in 2023, the 2025 figure fell to 405, with the policy changes credited for much of the reduction.
Carrying the message forward, scholars such as Ladd Keith of the University of Arizona’s Heat Resilience Initiative argue that cities should appoint a dedicated heat officer to coordinate efforts. “If nothing is responsible for heat, no one will tackle it,” Keith says.
Cities that are still unaccustomed to scorching temperatures can adopt cooling centres and ensure they remain open 24 hours. The city’s experience shows that resources such as reliable cool spaces and the promise of free or affordable air‑conditioning are key to preventing heat‑related deaths.
Climate scientists warn that heat waves are becoming more frequent, intense and long‑lasting as the planet warms beyond 1.1 degrees Celsius since the industrial era. Beyond public health, heat threatens infrastructure—roads buckle and flights get delayed—making it an economic and urban issue too.
Can Arizona’s Success Be Replicated elsewhere?
To spread Phoenix’s achievements, local governments must recognise heat as a chronic issue and plan for the elevated temperatures expected over the next decade. “We want to shift away from historical weather and start planning for the heat in 5–10 years,” Keith says.
In the short term, the Maricopa County’s success demonstrates that the combination of policy, infrastructure and community‑based support can reduce heat‑related deaths—even as new death investigations keep the number high in the present year.