Extreme Heat Is Reshaping Population Health and Healthcare Costs

Extreme heat is no longer simply a seasonal weather event. It is becoming an increasingly important population health challenge, with measurable effects on healthcare utilization, costs, and the well-being of the communities health plans serve.

For managed care organizations, this shift presents both a challenge and an opportunity. As climate-related health risks become more frequent, health plans can move beyond reacting to emergencies and instead use data, predictive insights, and community partnerships to better anticipate member needs and reduce avoidable healthcare utilization.

Extreme heat can worsen existing medical conditions and increase the risk of heat-related illness, dehydration, and complications among people with chronic conditions, including cardiovascular disease, kidney disease, respiratory disease, and mental and behavioral health conditions. As temperatures rise, these health risks can lead to more emergency department visits and hospitalizations, particularly among vulnerable populations.

New research from Elevance Health, conducted in collaboration with Carelon, underscores why this matters. The study, published in Health Affairs, analyzed healthcare claims from more than 44 million commercial, Medicaid, and Medicare Advantage members and found that additional days with a heat index of 100 degrees Fahrenheit or higher were associated with increased emergency department utilization and costs across nearly every population studied. Researchers also found higher rates of inpatient admissions among several populations, including Medicare Advantage members, adults enrolled in Medicaid, and commercially insured children.

Perhaps just as important, the research found that the greatest impacts were concentrated among populations already facing health and socioeconomic challenges. Emergency department utilization increased most among children enrolled in Medicaid, while Medicare Advantage members experienced the highest heat-associated healthcare costs.

These findings reinforce what many healthcare leaders already recognize: environmental risks often compound existing health disparities, making it even more important to identify and support people who are most vulnerable before they experience a health crisis.

As healthcare increasingly embraces whole-person care, climate-related health risks deserve greater attention alongside the clinical and social factors that shape health outcomes.

Fortunately, extreme heat is also one of the more predictable public health risks we face. Weather forecasts provide advance notice of dangerous conditions, creating opportunities for health organizations – payers, providers, health services, etc. – to intervene before people require often costly emergency care.

Health plans, for example, already use claims data and predictive analytics to identify members at risk for hospitalization, gaps in care, or worsening chronic disease. Incorporating environmental data into these existing population health strategies represents a natural next step. By identifying members whose medical conditions, age, or social circumstances make them particularly vulnerable to extreme heat, organizations can deliver timely outreach when it is likely to have the greatest impact.

That outreach may include reminders about hydration and medication management, assistance accessing transportation or cooling centers, ensuring continuity of prescription medications, or connecting members with telehealth services when travel becomes difficult or unsafe. Small interventions delivered before temperatures peak can help reduce avoidable emergency department visits while improving safety and experience.

Community partnerships are equally important to building resilience. Health plans cannot address climate-related health risks alone. Collaborating with local public health agencies, healthcare providers, community-based organizations, and emergency management partners can help ensure vulnerable individuals have access to critical resources during periods of extreme heat.

These partnerships also reinforce a broader understanding of population health. The conditions in which people live, work, and age continue to shape health outcomes in meaningful ways. Recognizing environmental exposure as another factor influencing health allows managed care organizations to better anticipate risks before they become costly medical events.

Climate resilience should also become part of routine operational planning. Just as organizations prepare for influenza season or other predictable surges in healthcare demand, they can incorporate extreme heat into seasonal planning, care management, patient/member communications, and emergency preparedness. Treating heat as a recurring driver of healthcare utilization, rather than an isolated weather event, enables more proactive decision-making across the healthcare system.

As climate-related health risks continue to evolve, managed care organizations have an opportunity to lead by combining data, prevention, and community collaboration to protect the health of the populations they serve.

Extreme heat may begin as a weather event, but its effects extend well beyond the forecast. By using predictive insights to identify vulnerable members, strengthening community partnerships, and integrating climate resilience into population health strategies, healthcare organizations can improve outcomes, reduce avoidable healthcare utilization, and build a more resilient healthcare system for the future.