Preparing and responding to extreme heat through effective local, state, and federal action planning

Heat risks are borne out of a combination of contextual factors (e.g., physical geography, planning efforts, political priorities, etc.) and the creation of vulnerability through exposure to the heat hazard (e.g., exposure, sensitivity, adaptive capacity, etc.). These heat-specific, contextual risks provide insight for formulating tailored strategies and technical guidance for devising heat-mitigation interventions that align with regional needs and climatic conditions.

Thus, heat action planning systematically and scientifically organizes short-, medium-, and long-term heat interventions within a spectrum of context-specific, socially, and fiscally responsive options. Integrating existing planning tools and risk assessment frameworks, similar to the broader-scale natural hazard mitigation planning process, offers a timely and effective approach to developing regionally tailored heat action plans. 

For heat action planning to succeed nationwide, multiple agencies and offices within the federal government need to 1) support state, local, tribal, and territorial (SLTT) governments with timely information and tools that identify specific guidelines, thresholds, objectives, and financial support for advancing interventions for extreme heat adaptation and 2) include extreme heat within their planning processes. Since all state and local public agencies are already involved in a wide variety of planning processes—many of which are requirements to receive federal investments—the focus on heat offers opportunities to integrate several currently disparate efforts into a comprehensive activity aimed at safeguarding the public’s health and infrastructure.

Challenge and opportunity

Few U.S. municipal governments are actively engaged in a systematic process that prepares local communities for extreme heat. For example, as of 2023, only seven U.S. states had a section dedicated to extreme heat in their Hazard Mitigation Plans (HMPs), as required by the Federal Emergency Management Agency (FEMA). Even when included within HMPs, the medium and long-term planning implications are consistently lacking. Planning for extreme heat’s current and future risk is not a requirement of many federally-mandated planning processes for SLTTs, limiting nationwide uptake. 

Despite decades of scientific assessments on risks to human health and infrastructure, there currently needs to be more precedent for developing comprehensive plans that address heat, nor the integration of risks with effective interventions. Many state, local, tribal, and territorial governments (SLTTs) are not planning for extreme heat and its future risk to populations. The appointment of Chief Heat Officers and other regional coordination efforts are currently limited, and the primary mechanism for heat response relies on emergency management. This short-term solution needs to be revised to prepare a region for ongoing and acute temperature increases. SLTTs and the federal government are just starting to invest billions of dollars in material services and non-material interventions, including tree plantings, air conditioning and heat pumps, white paints, cooling centers, new staff roles (i.e., Chief Heat Officers), and communication programs. 

Planning for future risks of extreme heat 

Further, as the federal government is just starting to assess its portfolio of assets and programs for heat resilience, it will need to consider future risks of extreme heat beyond immediate health and infrastructure risks to establish a fiscal agenda for risk mitigation. For one, extreme heat events are a catalyst for other destructive disasters, like wildfires and drought. Higher temperatures increase evapotranspiration rates, drying out grasses and trees and turning fallen branches into firewood. Compounding this are the shrinking snowpacks in western states, which make forests more flammable by reducing the water available for vegetation. All of these factors caused by excess heat — along with a history of unsustainable forest management practices and land use decisions — are contributing to more destructive wildfires. From 2017 to 2024, these wildfires came with an estimated $97+ billion in costs. 

Additionally, more surface evaporation (1) increases SLTT reliance on limited groundwater sources and (2) leads to less groundwater seepage and aquifer replenishment. Warmer temperatures also mean plants and animals need more water, further driving up consumption of this limited resource. All of these factors compound the growing risk of drought facing American communities. In 2023, over 80% of the United States Department of Agriculture’s (USDA) emergency disaster designations were for drought or excessive heat, and the costliest 2023 disaster was a combined drought/heat wave at $14.5 billion. The interactions and compounding risk of natural hazards are often unaccounted for in HMPs and other plans that consider hazard events in isolation. 

Federal support for risk mapping and planning

Existing federal initiatives to assist SLTTs in planning for extreme heat have focused on documenting extreme heat’s disparate impacts in cities and regions but do not strategically progress heat action planning. For example, the National Integrated Heat Health Information System (NIHHIS) is an interagency entity operated by the National Oceanic and Atmospheric Administration (NOAA) that manages www.heat.gov, and provides several opportunities for SLTTs to socialize and familiarize heat-related interventions. Since 2017, NOAA, in collaboration with NIHHIS, has supported the Heat Watch Campaigns, wherein SLTTs and community groups use temperature sensors to collect hyperlocal heat measurements. These sensors measure and collect temperatures every second, and the resulting maps describe differences in intra-regional heat, known popularly as “urban heat islands” (UHIs), which often vary by upwards of 20°F. These Heat Watch campaigns communicate heat as a local challenge and engage residents in socializing the potential impacts, while also advancing several initiatives and policies that aim to reduce the harmful effects of extreme temperatures. While almost all Heat Watch participating organizations have taken some immediate and often one-off actions, these campaigns have not advanced heat action planning through a systematic process. SLTTs have faced barriers to identifying promising adaptation strategies and resourcing necessary infrastructure improvements without dedicated, reliable follow-on investments. And, because most campaigns are conducted in urban areas, the Heat Watch campaigns currently do not capture the rural and ecosystem effects of heat. More systemic actions that integrate chronological and science-based applications of interventions that include the public, along with scientific assessments and contextual factors, are necessary for SLTTs to adapt.

Moreover, the federal government, which employs +3 million people, procures +$700 billion in goods and services annually, and delivers +$700 billion in financial assistance to states, locals, and private entities, must plan more effectively for extreme heat’s impacts on basic operations, services, infrastructure, and program delivery. As an example, the U.S. Department of Defense (DoD) has completed several assessments on heat (and continues to), and other agencies need to follow suit to ensure infrastructure and programs are resilient to future temperatures. The heat risks posed to basic operations can further strain vulnerable supply chains and put employees who are on the frontline of enabling and operating these Federal programs at risk of illness and death.

Plan of action

The heat action planning process requires five steps that help identify areas and populations that face disproportionate exposure to regionally-specific hottest temperatures and move towards interventions for mitigating extreme heat for SLTTs and the federal government:

Recommendation 1. Define “extreme heat” risk by local geography.

Extreme heat in Phoenix, AZ differs from extreme heat in Portland, OR; a week of 90°F in the Pacific Northwest can cause as many heat-related illnesses as a 110°F day in the South East.  A regional approach to characterizing the relevant risks is an essential first step. Developing heat hazard maps that describe the potential implications of extreme ambient temperatures on the public’s health, infrastructure, and critical services is essential to prepare SLTTs and the federal government. Existing “heat vulnerability indexes and maps” support the articulation of heat hazards, though they remain primarily passive interfaces that do not directly contribute to broader planning or policy processes. In addition, response to hazards requires local understanding and communication of existing risk, which is done by the National Weather Service (NWS) and FEMA through the Integrated Public Alert & Warning System. 

To define current and future “extreme heat” risk by local geography: 

1. FEMA, NOAA, USDA, Centers for Disease Control and Prevention (CDC), and the National Aeronautics and Space Administration (NASA) can collaborate on assessments of regionally-specific risk in the present and future, codifying cooling assets (potentially through ground-based assessments of summertime air temperatures, atmospheric dynamics, land use and land cover assessments), expected population acclimatization and existing health risks, and assessments of future climate conditions, such as ClimRR. Finally, USDA could assess agricultural growing zones for heat risk and better predict impacts on food and nutrition services supply chains.
2. HUD, EPA, and NOAA can work to identify localized exposure to extreme heat by expanding opportunities for monitoring indoor and outdoor air temperature in and around potentially vulnerable land uses (e.g., multifamily residential, older single-family residential, manufactured homes, and trailer parks), seeking additional funding from Congress where needed to develop and place these sensors.
3. FEMA can include metrics in its National Risk Index that characterize the building stock (i.e., by adherence to certain building codes), expected thermal comfort levels (even with cooling devices) under current and future climate conditions, and thermal resilience during power brownouts and blackouts. Additional focus on heat inequities will also help to advance approaches that center the public’s long-term health and safety.

Recommendation 2. Establish standards and codes for extreme heat resilience and risk mitigation.

Several federal agencies are directly involved in the development of standards (National Institute of Standards and Technology (NIST), Housing and Urban Development (HUD), Department of Energy (DOE), Department of Transportation (DOT), Environmental Protection Agency (EPA), FEMA, Department of Education (Ed)); however, we have no current designation for heat risk, certification of promising solutions, and identification of best practices for heat action planning. Once standards and guidelines exist, funding can accelerate the application of suitable technologies, analysis, and local engagement for developing heat action plans for SLTTs and federal government operations. Further, it is critical that adaptation solutions do not come at the risk of climate mitigation, for example, relying solely on air conditioning to keep people cool, which then leads to increased greenhouse gas emissions. Other strategies like urban forestry, building codes, and reflective materials in suitable locations will also need to be directly applied. 

To establish standards and codes for extreme heat resilience and risk mitigation: 

1. NIST, EPA, and U.S. Forest Service (USFS) can create “technology test beds” for heat resilience best practices, effectiveness evaluation, and associated benefits-costs analysis. 
2. DOE can work with stakeholders to create “cool” building standards and metrics with human health and safety in mind, and integrate them into building codes like ASHREI 189.1 and 90 series that can then be adopted by SLTTs. Where possible, DOE should explore evaluations of co-benefits of heat resilience with decarbonization and energy efficiency and work with state energy offices to implement these evaluations. Finally, DOE can also consider grid impacts during increasing periods of demand and conduct predictive analyses needed to prevent overload and prepare SLTT energy suppliers.
3. FEMA can integrate extreme heat considerations and thermal resilience within its National Strategy to Improve Building Codes.
4. HUD can update the Manufactured Home Construction and Safety Standards to require homes to perform a certain level of cooling under high heat conditions.
5. HUD and Ed can consider what safe thresholds for occupancy look like for residential settings and schools and provide guidance to SLTTs.
6. The Office of Management and Budget (OMB) and USFS can consider future risks to nature-based solutions (i.e., extreme heat) within different climate regions as a part of government-wide efforts to scale nature-based solutions.
7. DOT can consider requirements for infrastructure projects in SLTTs to mitigate UHI effects.

Recommendation 3. Operationalize interventions and coordinate amongst agencies that require SLTT planning processes.

While knowledge about heat exposure requires further assessment, integrating thresholds and programming to reduce preventable exposure to heat is necessary within planning processes, financial assistance delivery, and program and regulatory implementation. For example, an important next step will be establishing a heat tolerance threshold for occupations with higher heat exposure to ensure workers do not exceed core body temperatures. Currently, several wearable sensor technologies offer a direct means for firms to monitor the health of their outdoor workers. Such information can help develop material and non-material interventions that reduce the likelihood of heat stress and risk and ensure compliance with federal mandates and regulations. As another example, EPA, Health and Human Services (HHS), HUD, FEMA, Internal Revenue Service (IRS), and others can use new standards to implement federal funds or tax incentives. 

To better operationalize interventions and coordinate amongst agencies that require SLTT planning processes,

1. FEMA can incentivize Hazard Mitigation Planning for SLTTs that accounts for and emphasizes extreme heat risk as well as compounding disaster risk as a part of its National Mitigation Planning Program.
2. The Executive Office of the President (EOP) can consider its role in coordinating nationwide climate-risk planning, through auditing plans required by CDC, Administration for Strategic Planning and Response (ASPR), Federal Energy Regulatory Commission (FERC), Department of Transportation (DOT), FEMA, and other agencies for their readiness for future climate conditions (i.e. extreme heat). Where heat risk is not currently required in a federally-mandated plan, federal agencies should consider incentives to drive the adoption and uptake of heat action planning by SLTTs. 
3. OMB can identify potential regulatory pathways to build extreme heat resilience within SLTTs and federal government operations, considering technology standards, behavioral guidelines and expectations, and performance standards.
   1. Technology standards: Required presence of a cooling and/or thermal-regulating technology
   2. Behavioral guidelines and expectations: Required actions to avert overexposure
   3. Performance standards: Requirements that heat exposure cannot cross a certain threshold.

Recommendation 4. Support fiscal planning and funding prioritization.

Local jurisdictions must plan for many hazards and risks, and because heat funding is scarce and hard to get, it falls to the bottom of the list of priorities. Establishing a clear and accessible set of resources to understand the resources available to support heat adaptation and resilience can help to advance effective solutions. Further, SLTTs will get more funding to prevent past hazards, versus prepare for future ones like extreme heat. Current funding through FEMA and DOE is helping to shore up heat risk assessments and interventions in select locations, yet they remain inadequate for the scale of the challenge facing SLTTs. By prioritizing future climate risk in fiscal planning and funding, extreme heat resilience will become a larger priority because it can integrate into several programmatic and policy priorities, such as transportation, housing, and emergency response. The insurance and healthcare industries, operated by the Centers for Medicare and Medicaid (CMS) and Veterans Health Administration (VHA) can also play a larger role in shepherding heat resilience forward, by advancing beneficiaries that are adapting to extreme heat, and reducing emergency room visits due to heat illness.  

To support fiscal planning and funding prioritization,

1. OMB can work with federal agencies to perform a budget review of actual allocations to extreme heat activities, including financial assistance to SLTTs, as well as extreme heat’s existing risks to federal assets, critical infrastructure, programs, and workforce. OMB can collaborate with the General Services Administration (GSA) on federal workforce and contractor workforce safety protections and VHA, Department of Justice (DOJ), U.S. Army Corps of Engineers (USACE), DOT, Cybersecurity and Infrastructure Security Agency (CISA), DOE, and other relevant agencies on operations of critical infrastructure during current and future heat events.
2. OMB, in collaboration with EPA, FEMA, DOE, and NIST, can produce a report that identifies gaps in funding to advance heat mitigation and preparedness efforts.
3. HUD, FEMA, EPA, and others can recommend recipients of federal financial assistance adhere to building and energy codes that ensure thermal comfort and resilience.
4. Treasury can investigate potential insurance options for covering the losses from extreme heat, including security from utility cost spikes, real-estate assessment and scoring for future heat risk, “worker wage” coverage for days where it is unsafe to work, protections for household resources lost during an extended blackout or power outage, and coverage for healthcare expenses caused by or exacerbated by heat waves that CMS could incentivize.
5. The Securities and Exchange Commission (SEC) can price climate risk when deciding on interest payments for municipal bonds for SLTTs and give beneficial rates to SLTTs that have done a full analysis of their risks and made steps towards resilience.

Recommendation 5. Build evaluative capacity of extreme heat resilience interventions.

There is a need for designated bodies that evaluate and monitor the effectiveness of specific heat mitigation interventions to make systematic improvements. Universities, research non-profits, and many private organizations have deep expertise in evaluating and assessing heat-relevant programs and projects. Such programs will need to be developed through universities and through private-public partnerships that support SLTTs in ensuring that specific actions are effective and transferable. 

To build out the evaluative capacity of extreme heat resilience interventions,

1. GSA can demonstrate low-power, passive and resilient cooling strategies in its buildings as a part of “Net Zero” initiatives and document promising strategies by climate region. DOE can also conduct more demonstration projects to build strategies that ensure indoor survivability in everyday and extreme conditions.
2. EPA and NOAA can administer research and evaluation grants to assess, identify, and promote heat mitigation actions that are effective in reducing heat risks across diverse geographies as well as design effective heat action planning strategies for SLTTs. This could look like further expansion and institutionalization of the NIHHIS Centers of Excellence program.

Conclusion

In all scientific estimates, 2024 will be the next hottest year on human record, and each year thereafter is likely to be even hotter. Under even existing climate conditions, thousands of Americans are already unnecessarily dying every year, and critical infrastructures like grids are being pushed to their limits. With temperature trends point to ever-hotter summers, effective and strategic heat adaptation planning within SLTTs and across the federal government is a national security priority. Through the broad uptake and implementation of the Heat Action Planning framework by key agencies and offices (EOP, OMB, Treasury, SEC, NOAA, USDA, CDC, NASA, HUD, DHS, FEMA, NIST, EPA, USFS, DOE, DOJ, DOT, ASPR, GSA, USACE, VHA, SEC, and others), the federal government will enable a more heat-prepared nation.