Much of the Northern Hemisphere is experiencing extreme heat this summer, with France reporting over 2,000 additional deaths during a late June heatwave and England and Wales estimating more than 2,700 heat-related deaths since May. The United States recorded at least 44 heat-related deaths during the 4 July holiday weekend. Scientists have indicated that these elevated temperatures represent a new baseline for affected communities, with nighttime temperatures failing to cool sufficiently for bodies to recover from daytime heat exposure.
Phoenix, Arizona, and Maricopa County have emerged as leaders in heat-response planning after years of managing consistently high temperatures. The county made history by hiring the first heat officer of any city worldwide in 2021. Policy interventions have focused on expanding access to cooling centers and air conditioning services for vulnerable populations, including low-income residents and people experiencing homelessness. The county extended operating hours at cooling facilities, with some locations now open 24 hours, while also launching programs providing repairs or replacements for residential air conditioning systems.
These efforts appear to have yielded measurable results. Heat-related deaths peaked at 645 in 2023 before declining to 405 in 2025, a reduction that experts partially attribute to the implemented policy changes. However, early data from this year suggests the decline may not be sustained, with 23 confirmed heat-related deaths recorded as of 11 July and 282 additional cases under investigation.
Experts suggest other jurisdictions could adopt similar strategies, including appointing dedicated heat officers to coordinate initiatives across government agencies. They emphasize that heat must be recognized as a multifaceted challenge affecting public health, infrastructure, and economic activity. Climate scientists stress that current warming represents a permanent shift rather than a temporary anomaly, with global temperatures continuing to rise despite emissions reductions. Planning frameworks must shift from historical temperature patterns to projections for the coming five to 10 years, researchers caution.