How Extreme Heat Connects to Healthcare Use and Costs
Key Highlights:
- An Elevance Health and Carelon Research study used an extensive dataset to examine associations between extreme heat and healthcare use and costs.
- Researchers found links between extreme heat and increased emergency department use and costs, as well as associations between heat and inpatient hospital admissions.
- The study highlights how climate-related factors can affect health, and the importance of strategies that strengthen community readiness and support access to care.
Extreme heat is more than a weather event. Like other climate-related factors, it can also be considered a health event — one with ties to both healthcare use and costs, according to findings from Elevance Health and Carelon Research.
In a study notable for the depth and breadth of its sample size, researchers analyzed temperature and humidity data alongside claims data from over 44 million members of commercial, Medicaid, and Medicare Advantage plans affiliated with Elevance Health. Their findings provide insight into exposure to extreme heat and healthcare use, who’s likely to be most affected by higher temperatures, and how those temperatures are associated with healthcare costs.
“Extreme heat is already shaping healthcare use and costs in measurable ways,” said Hakon Mattson, vice president of sustainability at Elevance Health. “Understanding that connection is essential to helping us better support people and communities.”
Findings: The analysis shows that emergency department (ED) use and costs increased across nearly every group studied by age and type of plan coverage when the heat index reached at least 100 degrees within a week, compared with when the index sat at a more temperate level. Inpatient hospital admissions also increased among members with certain types of health coverage.
Researchers did not find a link between extreme heat and routine outpatient care, such as visits to a primary care provider, or with outpatient or inpatient costs. Such findings “may have been driven by avoidance behavior and the cancellation of elective procedures and visits during extreme heat,” according to the study.
Who’s Most Affected: The study highlights how climate-related risks like extreme heat can disproportionately affect many people already experiencing health and socioeconomic challenges. While emergency department use and costs increased for nearly every group in connection with extreme heat, ED use rose the most among children with Medicaid coverage. Costs rose the most among Medicare Advantage members and adults with Medicaid coverage.
Hospital admissions tied to hotter days increased the most among children with commercial coverage, followed by Medicare Advantage members and adults with Medicaid coverage. Overall, heat-associated healthcare costs were highest among Medicare Advantage members.
Why It Matters, and What’s Next: The study points to how the conditions in which people live shape their health and how environmental exposure can influence the cost of care. As a partner in health for the people we serve and their communities, we work to address these risks through a whole-health approach that strengthens community readiness, supports uninterrupted access to care, and enables rapid response during emergencies. We’re focused on reducing healthcare’s environmental footprint and on building resilience into our business operations, ensuring we remain ready to support our members.
We’re also advancing research that can be translated into proactive support for members and communities. This study follows a similar analysis from Elevance Health researchers that linked heat to increased ED visits by people with chronic kidney disease.
“Climate-related factors like extreme heat clearly affect people’s health,” Mattson said. “By understanding and addressing those risks, we have an opportunity to improve health outcomes, lower costs, and build a more resilient and sustainable healthcare system for the future.”
Methodology: Researchers analyzed healthcare claims from 2016–2023 for more than 44 million people and calculated heat index measurements by census tract. They used statistical modeling to estimate how an additional day of extreme heat in a week — compared with more temperate conditions — was associated with changes in healthcare use and costs among different groups divided by age and insurance plan coverage. Additional analyses tested the consistency of the results and examined geographic variations.
Frequently Asked Questions
How does extreme heat affect healthcare use?
Extreme heat can affect healthcare use and outcomes by leading to increased emergency department (ED) visits, hospitalizations, and mortality. A recent Elevance Health analysis found associations between extreme heat and ED use and costs across nearly all groups studied when broken down by age and type of health insurance coverage. Increased hospital admissions were also associated with extreme heat among some groups.
How can extreme heat impact healthcare costs?
Extreme heat can impact healthcare costs by increasing the need for certain types of care, especially emergency care. The Elevance Health study found that emergency department use and costs increased in connection with extreme heat across nearly every age and coverage group studied.
Who is most affected by extreme heat-related health risks?
Extreme heat can disproportionately affect people who are already experiencing health and socioeconomic challenges. The Elevance Health study found emergency department use associated with extreme heat increased the most among children with Medicaid coverage, while ED costs rose the most among Medicare Advantage members and adults with Medicaid coverage.