Heat waves create a health and safety risk for communities in Los Angeles (LA) County and throughout the world. Both 2023 and 2024 set new records as the hottest year ever, and longer and increasingly intense heat conditions are happening more often than before. Emergency department visits for heat-related illness spike during heat waves. Some groups are more vulnerable to heat, including older adults, young children, pregnant people, unhoused individuals, outdoor workers, athletes, and people with chronic medical conditions, because extreme heat can worsen conditions such as cardiovascular, respiratory, cerebrovascular disease, and diabetes-related conditions.

Protecting residents and workers from health impacts, including heat-related illness and death, is a critical responsibility of government. LA County is one of many jurisdictions across California and the country that are adapting to the increasing heat, both through policy and practice.

In January 2024, the LA County Board of Supervisors passed a motion directing the Department of Public Health to work with other County departments to create a safe maximum temperature threshold for residential units, gather stakeholder input, and prepare a draft ordinance.

To begin the process, Public Health reviewed local ordinances from across the country, assessed relevant literature on the establishment of indoor air temperature standards, commented on the California State Assembly Bill 209 draft report prior to the release of the Final Report in early 2025, and gathered input from key stakeholders.

The ordinance was passed by the Board of Supervisors on August 5, 2025, and enforcement will begin in January 2027.