Maricopa County / Phoenix, USA
#00188
Case study of
#00189 Designate a free climate-shelter network in existing public buildings
Implementer
City of Phoenix Office of Heat Response and Mitigation and Maricopa County, with regional cooling and respite partners
Timeline
Since Jan 1, 2024
Location
Description
A turnaround case for how cooling and respite sites are run, not just where they are. Through 2023, the region's cooling centers were largely daytime-only, and they failed the population at highest risk: heat deaths in Maricopa County climbed to 645 in 2023, about half among people experiencing homelessness, who had nowhere to go overnight when temperatures stayed dangerous.
From 2024 the model shifted: 24/7 and overnight respite centers, extended hours at cooling sites, transport to sites arranged through the 211 line, and street outreach carrying naloxone and electrolytes. Heat deaths fell to 608 in 2024 (the first decline in a decade) and 430 in 2025 (final county report, April 2026).
The outcome remains partial: 48 percent of 2025 heat deaths were still people experiencing homelessness, and mortality causation is not attributable to the shelter changes alone (the wider heat office program also expanded).
Metrics
2Funding
Lessons learned
- Daytime-only cooling centers structurally fail people experiencing homelessness; overnight heat is when unsheltered deaths accumulate, so 24/7 respite is the load-bearing change.
- Transport (via the 211 line) and street outreach with naloxone and electrolytes are part of the shelter system, not add-ons; substance use and heat mortality overlap heavily in this population.
- Deaths fell two years running after the shift (645 to 608 to 430), but 48 percent of 2025 deaths were still unhoused people; respite hours mitigate but do not substitute for housing.
- Attribution is to the whole regional heat program; the respite-hours shift is the most direct mechanical link to the unhoused death toll.
Documented Jul 24, 2026