Extreme Heat Governance: A Critical Analysis of Heat Action Plans in California

Michael T. Schmeltz, DrPH, MS; Jason A. Smith, JD, MTS; Isabella Olmos, BS; Erin Quintero, BS


Am J Public Health. 2023;113(1):15-19. 

In This Article

Abstract and Introduction


Extreme heat events have adverse effects on population health, causing heat-related illnesses, such as heat exhaustion and heat stroke, but also exacerbating underlying medical conditions, such as cardiac and respiratory diseases, through various mechanisms.[1] In the United States, from 2000 to 2010 there were approximately 28 000 recorded heat-related hospitalizations, and between 2004 and 2018, an average of about 700 people died because of heat-related illnesses, making heat the deadliest weather-related hazard in the United States.[2,3] These figures do not represent heat morbidity and mortality that were not attributable by International Classification of Diseases (Geneva, Switzerland: World Health Organization) Ninth Revision (1980) or 10th Revision (1992) code to a confirmed diagnosis of heat-related illnesses, which likely results in underreporting.[4] Additionally, the health consequences of extreme heat are amplified by sociodemographic vulnerabilities and our built environment. As extreme heat events continue to increase in frequency and intensity, individuals, communities, and the municipalities in which they live will need to prepare and adapt.


Health impacts from high ambient temperatures have led many municipalities to develop plans to respond to extreme heat events. These plans are sometimes referred to as excessive heat emergency plans, heat-health response plans, or heat action plans (HAPs). Many European countries implemented HAPs following the 2003 European heat wave.[5] In the United States, a number of cities have developed HAPs,[6,7] although the vast majority of US cities and regions rely only on local National Weather Service offices to issue heat advisories based on heat index forecasts that may not be linked to local HAPs.[8]

In 2020, the US Centers for Disease Control and Prevention (CDC) released a technical report on the summary and strategies for HAPs and ascribed their focus to emergency response planning or long-term planning for extreme heat. The report identifies that plans can stand alone or be an annex to an all-hazards plan and specifically identifies emergency preparedness and management activities when coordinating plans.[9] Although the CDC report is not a step-by-step guide or an all-inclusive approach to how to specifically prepare or coordinate a HAP, the reference to emergency operations plans and the location of HAPs in all-hazards mitigation plans suggest that extreme heat is an event that consistently requires an emergency response and is best understood in that context. However, climate change will increase the likelihood and frequency of extreme weather events, such as extreme heat, and these events have increased substantially over the past decades and will continue to affect regions of the globe regularly.[10] We argue that the increasing frequency and regularity of these events move them from emergencies to an issue to be planned for with preventive health plans.

Since the terrorist attacks of September 11, 2001, the public health legal frameworks that emphasized preparedness have shifted to a concept that emphasized emergencies. This framing emphasizes an emergency as an event that overwhelms the capacity of the health care system.[11] One of the defining characteristics of an emergency is its unpredictability or its unforeseeability. Given that these events will be more frequent, the health and public health systems must move the approach to extreme heat events from emergency to more traditional public health governance structures, usually located in departments of public health or in close coordination. This move supports two very important conceptual shifts. First, it situates the effects of the climate crisis more clearly in the regular governance structures of the state as a long-term policy consideration. Second, it supports the transition of our public health care systems to a climate-resilient model. Keeping the frameworks entirely in offices of emergency services abrogates the duty of the state to grapple with the climate crisis as a long-term reality.

Public health departments can be ideal partners and leaders in addressing climate and health issues, particularly those at the local jurisdiction. They are usually the designated government agency that is tasked with protecting the health of communities, are a trusted voice with close ties to the communities they serve, and have a proven ability to confront and overcome complex health issues, such as climate change.[12] Guidance on HAPs is not new but has not been implemented equally across regions. Additionally, even information about extreme heat on local and regional government Web sites can be sparse, and coverage is not always the same.[13]

We used local public health jurisdictions in California to examine how HAPs are organized and implemented to protect populations from the health impacts of extreme heat. We argue that extreme heat events should be in the jurisdiction of public health response and that these organizations are key to leading or closely supporting efforts to reduce the health impacts associated with extreme heat.