To: National Governors Association, 444 North Capitol St NW #267, Washington, DC 20001
Date: July 22, 2025
Extreme heat is a national public health emergency with rapidly worsening impacts across the United States. Extreme heat is making us sicker, aging us faster, and is one of the leading causes of weather- related mortality. In 2023 alone, an estimated 2,300 people died from extreme heat. Using excess death attribution, true mortality is likely 10,000+ annually.
The 108 undersigned organizations and 32 endorsing organizations, representing health professionals, public health experts, and health advocates across the country, support strong preparedness policies that can prevent the worst health harms of extreme heat. Our members work hard to care for our patients and communities before, during, and after the disaster strikes. But we can’t do it alone. To protect the populations we serve, we need the leadership of our Governors. With your partnership, we can advance policy solutions that keep our populations healthy, even during the worst extreme heat events.
To build preparedness to extreme heat, we recommend the following four policy priorities:
- Launch statewide assessments of extreme heat impacts and invest in robust health surveillance systems to track heat-related illness, economic costs, and social disruptions.
- Designate a statewide heat lead and develop a whole-of-government extreme heat
- Consider extreme heat as a state of emergency to mobilize needed
- Develop strategies to finance and plan for long-term extreme heat impact
The Health Harms of Extreme Heat
High temperatures pose life-threatening health risks, causing direct heat illness like heat stroke; exacerbating underlying medical conditions, such as cardiovascular, respiratory, and kidney disease; raising the risk for adverse birth outcomes; and disrupting access to essential healthcare, especially for vulnerable communities like the elderly and those living in poverty.
Pharmaceutical interactions also pose a notable risk. Certain medications can inhibit the protective mechanisms the body uses to regulate temperature. These disruptions can impair the body's ability to cool itself effectively, leading to dangerous overheating.
In addition, air pollution increases when temperatures rise. Volatile organic compounds react chemically to sunlight exposure and heat, leading to increased production of ground-level ozone, which can reach levels dangerous to human health. Ozone exposure can harm both acute respiratory functions and cause chronic health issues, including increased rates of respiratory illnesses, metabolic disorders, nervous system issues, reduced fertility and poor birth outcomes, and increased respiratory and cardiovascular- related mortality.
Populations with greater risk of exposure to extreme heat, such as people who work outside or people without reliable cooling access, children, and the elderly will feel the heat first and worst. About 36 million U.S. employees experience heat exposures on the job, a quarter of all U.S. households cannot pay their energy bills, and 36,000 U.S. schools either lack air conditioning or have outdated HVAC systems. In the event of blackouts, hundreds of millions of Americans are at risk of exposure to dangerous temperatures that will negatively impact their health due to reliance on air conditioning. The North American Electric Reliability Corporation (NERC) has warned that two-thirds of the U.S. face energy reliability challenges because of heatwaves.
Extreme heat also contributes to the rapidly escalating cost of living. People working paycheck to paycheck are being forced to choose between air conditioning on sweltering days and basic necessities like food and medication. This will compound the economic costs of heat to our broader system: decreased worker productivity, shrinking business revenues, agricultural and raw product damage, heat-intensified wildfires and droughts, and power grids pushed to the brink. In 2024, the impacts of extreme heat cost an estimated $ 162 billion – equivalent to nearly 1% of the U.S. GDP.
The Impacts of Extreme Heat on Health Systems
States are seeing increasing death tolls and health harms from both chronically elevated temperatures and acute, unprecedented heat waves. This is happening in “hot” places and “cool” places. At the front lines of heat, Arizona saw over 600 heat-related deaths in Maricopa County in 2024, more than triple the number compared to just five years prior. In 2021, a heat dome settled across the Pacific Northwest, spiking temperatures to 40°F above average. The extreme temperatures caused roads to buckle, increased electricity demand to record highs, overwhelmed emergency services, and overheated healthcare facilities. When the heat subsided, there were more than 600 excess deaths.
Health systems are the first line of response to the health impacts of heat, and the system is facing increasing demand for extreme heat-related care. In Texas, children’s heat-related ER visits have nearly tripled over the past decade, and the state saw 450 deaths in 2023. Florida leads the nation in heat-related illness and ER visits as of 2024. And Southern Nevada saw a 30% increase in ER visits and over 500 deaths in 2024. Meanwhile, in Northern states like Massachusetts, extreme heat overwhelmed unprepared health systems in 2024. And in Missoula, one of Montana’s largest cities, preliminary analysis of 2020 data found that extreme temperatures notably increased the 911 call volumes. Nationally, healthcare costs related to heat illnesses are now $1 billion a year, a number only expected to grow as summers get hotter.
The system-wide impacts of extreme heat will increasingly stress our national health care system, which already suffers from widespread staff shortages and burnout, rising costs, unequal access to care, and high rates of preventable illness. Heat-driven increases in 911 calls, emergency room visits, and mortality rates of many vulnerable communities will only compound these crises. Without comprehensive action, the public health burden of extreme heat will continue to escalate across every region of the country. Our health systems do not have the capacity to face this crisis alone.
The most effective way to prevent deaths and economic losses from extreme heat is to act before heat hits.
State-level action on extreme heat is urgently needed to minimize the growing impacts and emergent risks. States must understand the scale of the problem, ready their emergency management systems to respond, and develop long-term strategies to address heat-related impacts to public health, the economy, and the built environment. To do this, we affirm the following four policy priorities to our state leaders:
Priority #1: Launch statewide assessments of extreme heat impacts
You cannot improve what you do not measure. Better tracking of heat-health and economic impacts will allow for state leadership to understand the current impacts and evaluate outcomes from applying different preparedness and mitigation strategies. To establish a baseline, states should initiate a state-wide study of the impacts and costs of extreme heat events. For example, California’s Department of Insurance pioneered a heat-impacts assessment that found that the total impact of seven extreme heat events in the state was $7.7 billion and 460 deaths. Ohio’s Heat Risk Assessment quantified the costs associated with extreme heat for the state.
To support this and ongoing evaluation, states will also need to strengthen syndromic surveillance systems to monitor heat-health impacts and sources of risk to public health. Leading examples of heat-health surveillance include Washington State’s Heat Stress Data and New York State’s Heat Surveillance Report.
Additional health and wellbeing-related impacts that should be tracked include pregnancy-related outcomes, school closures and student absenteeism, and rises in requests for health-related social needs, like housing.
Priority #2: Designate a statewide heat lead and develop a whole-of-government extreme heat plan.
To address extreme heat, Governors need to establish state leadership, either by designating a Chief Heat Officer or assigning responsibility to a department with broad coordination capabilities. Arizona created a state-wide Chief Heat Officer while New Jersey assigned the responsibility for heat planning and action coordination to its Resilience Office. Once leadership is established, the state should initiate a whole-of- government planning process to prepare for, respond to, and reduce the risk of extreme heat. Holistic strategies to reduce the risk of extreme heat exposure include heat safety workplace regulations and workers’ compensation incentives, nature-based solutions and land use planning, grid reliability build-out, energy storage, and back-up power, smart surfaces and shading, and enhanced building codes. States with whole-of-government heat plans include California, Arizona, New Jersey, and New York.
A critical first step in planning and preparedness is to create an emergency playbook for extreme heat events, bringing together emergency management, public health, social services, and medical care. This should include the following: understanding what triggers an emergency, designating incident periods and command, assessing workforce needs to care for the impacted populations, laying out possible policy actions (e.g., regulatory waivers, shut-off protections, eviction moratoria, interstate workforce compacts), tracking operational needs of key response assets like ambulances and hospital beds, and, if the need arises, formulating expected damages and requests for the federal government. In particular, the playbook should include scenario planning for partial or complete power system failure during a heat wave, which would be an especially deadly combination.
Engaging the public health, social services, and medical care communities is critical to ensure the health workforce is prepared to care for those impacted by extreme heat and cascading disasters. For example, in response to the deadly 2021 heat dome, Washington State developed a statewide heat response plan, an effort driven in large part by public health and health care institutions through healthcare coalitions.
Priority #3: Consider extreme heat as a state of emergency to mobilize needed resources.
Heat has been elevated as a state-wide emergency in states like Oregon, Arizona, California, and Louisiana. When responding to extreme heat events, states should prioritize safeguards that protect the most lives from extreme heat, such as preventing utility shut-offs, deploying microgrids, back-up power and energy storage to prevent widespread power failure and its cascading negative health impacts, and dispatching additional emergency response and medical personnel to treat the increased influx of people with heat illness. State action is particularly critical for safeguarding small towns and rural areas, which lack the local emergency management and public health capacity to address extreme heat.
The Federal Emergency Management Agency (FEMA) acknowledged in a response to a rulemaking petition on extreme heat that extreme heat can qualify as a major disaster, as this designation includes “any natural catastrophe.” To prepare to make that request for Federal disaster assistance, Governors must have a heat emergency plan in place and have a system to estimate damages and losses from extreme heat. Extreme heat can also be designated as a Public Health Emergency by the Health and Human Services (HHS) Secretary. Without a co-occurring major disaster declaration, HHS can waive regulatory requirements for its grants and programs, hire and reassign personnel, speed up data collection, and access emergency funds. With a major disaster declaration, HHS can issue 1135 waivers to expand access to patient care, such as creating pop-up outdoor triage centers for heat-exposed patients.
Our members are particularly concerned about the current state of federal emergency response infrastructure heading into this disaster season. Numerous statements by members of the current administration have suggested that FEMA’s disaster-response capacity may be reduced or even eliminated in the coming months. Proposed and ongoing restructurings at HHS, such as the merging of components of the Administration for Strategic Preparedness and Response with the Centers for Disease Control and Prevention, will impact lines of communication between state health departments and their federal counterparts. All of this uncertainty highlights the need for state-level preparedness and action on extreme heat as well as the need for Governors to build and support the case for national preparedness and response infrastructure.
Priority #4: Develop strategies to finance and plan for long-term extreme heat impact reduction.
Year after year, temperature records have been broken, and deaths from extreme heat are only accelerating. States must invest in forward-thinking solutions that mitigate the long-term health and fiscal risk of extreme heat. This looks like:
- Prioritizing risk reduction strategies across state budgets, such as implementing heat protections for state employees and incentivizing workplace heat safety best practices as a way to reduce workers' compensation claims.
- Research shows that interventions like rest, water, and shade not only prevent heat-related illness and injury but also boost worker productivity.
- Identifying multifaceted interventions to built environments when conducting infrastructure build-out, zoning ordinances, and capital planning.
- This might include passive cooling strategies like trees and green spaces, reflective roads, sidewalks, and parking lots, cool roofs, shade structures, and high-albedo materials that reduce urban heat temperatures, lower the cost of cooling for consumers, and reduce grid strain, decreasing the risk of blackouts.
- Emphasizing the importance of funding for response to and mitigation of extreme heat to the federal government.
- This includes assessing and uplifting the needed federal support to respond to extreme heat, through the Stafford Act and the Public Health Emergency authorities, Hospital Preparedness Program, Medicare and Medicaid and the Low-Income Home Energy Assistance Program, as well as reduce long-term risk through funds like the Weatherization Assistance Program, Home Energy Rebates and Tax Credits, Rural Energy for America Program, Hazard Mitigation Grant Programs, and the Urban and Community Forestry Program. States should also use their convening power to call upon the private sector to prioritize financing of strategies that reduce long-term heat risk.
The time to act is now.
The federal government’s proposed reductions to public health surveillance, preparedness funding, and mitigation programs, as well as emphasis on state-level action, signal a call for leadership to step in and minimize extreme heat’s risk to communities. Extreme heat’s harms will only grow, and continue to strain our health workforce and system capacity. We are doing everything in our power to care for those already suffering the consequences of extreme heat. But prevention must come before a crisis. That’s why we are calling on you—our Governors—to lead with urgency and foresight.
As trusted voices for our patients, we need your help to implement plans and policies to protect people before they need medical interventions. By acting on the four policy priorities outlined in this letter, you can protect lives, stabilize our health systems, and ensure a healthier future.
Signed,
Academy of Physician Associates in Cardiology
African Heritage PA Caucus
Allergy and Asthma Network
Alliance of Maine Health Professionals for Climate Action
Alliance of Nurses for Healthy Environments
American Academy of Pediatrics
American Academy of Pediatrics, CA Chapter 3
American Academy of Pediatrics, DC Chapter
Arkansas Chapter, American Academy of Pediatrics
Delaware Chapter, American Academy of Pediatrics
Florida Chapter of the American Academy of Pediatrics
Maine Chapter, American Academy of Pediatrics
Maryland Chapter, American Academy of Pediatrics (MDAAP)
NYS AAP - Chapter 2
NYS AAP - Chapter 3
Virginia Chapter, American Academy of Pediatrics
Washington Chapter of the AAP
West Virginia Chapter, American Academy of Pediatrics
American Association of Occupational Health Nurses
American College of Occupational and Environmental Medicine
American College of Physicians
American College of Radiology
American Lung Association
American Medical Women's Association
American Public Health Association
Arizona Public Health Association
Florida Public Health Association
Georgia Public Health Association
Oregon Public Health Association
South Carolina Public Health Association
Southern California Public Health Association
Asthma & Allergy Foundation of America - MI Chapter
BLKHLTH
Boston Children's Hospital Department of Sustainability
California Chapter of the American College of Emergency Physicians
California Nurses for Environmental Health and Justice
Carolina Advocates for Climate, Health, and Equity
Children's Environmental Health Network
Climate Code Blue
Climate for Health/ecoAmerica
Climate Health Now
Climate Psychiatry Alliance
Clinicians for Climate Action NJ (CCANJ)
Colorado Academy of Family Physicians
Concerned Health Professionals of New York
Delaware Nurses Association
Florida Clinicians for Climate Action
Georgia Clinicians for Climate Action
Georgia State Medical Association, Inc.
Health Care Without Harm
Health Professionals for a Healthy Climate
Healthcare Ocean
Healthy Air and Water Colorado
Healthy Climate New Mexico
Healthy Climate Wisconsin
Idaho Clinicians for Climate and Health
Illinois Clinicians for Climate Action (ICCA)
Jessica Holton, PLLC
Madison Manual Medicine
Maine Medical Association
Mass General Brigham
The Medical Society Consortium on Climate and Health
Medical Students for a Sustainable Future (MS4SF)
Meridian Health Care Providers
Michigan Clinicians for Climate Action
Mid Atlantic Alliance on Climate and Health
Migrant Clinicians Network
Mothers & Others For Clean Air
Moms Clean Air Force and EcoMadres
Montana Health Professionals for a Healthy Climate
National Association of Hispanic Nurses
National Association of Pediatric Nurse Practitioners
National Commission on Climate and Workforce Health
National Environmental Health Association
National League for Nursing
Nevada Clinicians for Climate Action
NH Healthy Climate
Northwest Washington Indian Health Board
NY Clean Air Collective
OUCH-Int'l (Oncology Advocates United for Climate and Change - International)
Physicians for Social Responsibility
Greater Boston Physicians for Social Responsibility
Oregon Physicians for Social Responsibility
Physicians for Social Responsibility, Colorado
Physicians for Social Responsibility, Florida
Physicians for Social Responsibility - Kansas City
Physicians for Social Responsibility Maine
Physicians for Social Responsibility - New York
Physicians for Social Responsibility Pennsylvania
Physicians for Social Responsibility, San Francisco Bay
Physicians for Social Responsibility Texas
Physicians for Social Responsibility Wisconsin
Washington Physicians for Social Responsibility
Puerto Rico Clinicians for Climate Action
Rapid Anthropology Consulting
Redstone Global Center for Prevention and Wellness
SafeWork Washington
The Science and Environmental Health Network
Sextant Foundation
Society for Reproductive Endocrinology and Infertility
Society of Latinx Nurses
UCSF Medical School
Utah Physicians for a Healthy Environment
Vibrant Emotional Health
Virginia Clinicians for Climate Action
VT Climate and Health Alliance
Wisconsin Environmental Health Network
Worksafe