Cooling Is the New Heating: Heat, Health, and the Air-Conditioning Gap

The hazard that moved

For most of the modern history of energy assistance, the danger to watch was cold. Programs were built around winter, around keeping the heat on, around the documented harms of a cold home. That framing is increasingly out of step with current conditions. Extreme heat is now the fastest-growing weather-related health threat in much of the country, and the systems meant to protect vulnerable households were largely designed for the opposite season.

This primer makes the case that cooling has become a health necessity on par with heating, that access to it is unevenly distributed in ways that cost lives, and that the response carries a genuine tension: air conditioning saves lives during heat waves while adding to household energy bills, so the households most exposed to dangerous heat are often the ones who ration the very cooling that would protect them.

Heat as a health emergency

The body cools itself by sweating, and when heat and humidity climb past certain points that mechanism fails, leading to heat exhaustion and heat stroke. Nighttime heat matters as much as the daytime peak, because a home that never cools down denies the body its recovery period. The people most at risk are familiar from every other chapter of this series: older adults, infants and young children, people with chronic conditions, outdoor workers, and residents of poorly insulated or low-income housing.

The scale is no longer abstract. Heat-related deaths have been rising sharply year over year, and heat is widely understood to be undercounted on death certificates because it often presents as a cardiovascular or respiratory event with heat as the hidden contributor. Single jurisdictions now record thousands of heat-related emergency room visits in a bad summer. The danger that programs were built to treat has effectively switched seasons, and the institutional response has been slow to follow.

The cooling gap

Access to cooling tracks income and race closely. Households without reliable air conditioning, or without the ability to afford running it, are disproportionately low-income and disproportionately communities of color, and they sit in the same neighborhoods that carry the heat-island effect of dense pavement and little shade. The result is a cooling gap layered directly on top of existing health disparities.

The behavioral evidence is telling. Studies that look at when households actually switch on cooling have found that low-income households wait meaningfully longer into dangerous heat before turning on the air conditioning than higher-income households do, because they are weighing the bill against the discomfort. That waiting is invisible to an income-based eligibility screen, and it is exactly the margin where heat illness develops.

The policy mismatch

The country's main energy-assistance program reflects the older framing. Cooling assistance has historically received only a small share of LIHEAP funds, on the order of single-digit percentages, even as cooling need grows. Funding has tilted toward cold-weather states while hotter regions with higher cooling needs and higher energy insecurity have received proportionally less, a spatial mismatch between where the money goes and where the heat is. In at least one recent summer, a state's cooling-assistance benefit exhausted its funding within days of opening, during the season's first heat wave.

There is legislative recognition of the problem, with proposals to expand and rebalance assistance toward cooling and to strengthen the data collected on energy burden and disconnections. The recognition matters, but it underscores how far the existing infrastructure was built for a different hazard.

The tension worth holding

This is where an honest primer has to sit with a real bind. Air conditioning is a proven, life-saving adaptation during extreme heat. It is also an energy cost that raises household burden, which is why the households most exposed to heat are so often the ones who ration the cooling that would protect them. Pushing cooling without attention to efficiency and cost can deepen energy poverty even as it reduces heat deaths.

The resolution is not to choose between cooling and affordability but to pair them. Efficient cooling, including the ground-source and high-efficiency systems discussed elsewhere in this series, and passive measures such as shade, insulation, and reflective surfaces together make it possible to keep people safe without trapping them in higher bills. The goal is cooling that does not cost a household its budget.

What this means for community health infrastructure

Heat is intensely local. Risk varies block by block with housing quality, tree canopy, and the age and health of residents, which means the response has to be local and well-informed. A community that can map its own heat vulnerability, knowing which residents lack reliable cooling, which blocks run hottest at night, and who is medically fragile, can place cooling resources, open cooling centers, and target efficiency upgrades where they prevent the most harm.

That mapping and the durable arrangements built on it are the kind of governed, community-held infrastructure the Foundation works on. The hazard has moved from cold to heat faster than institutions have adapted. Closing the cooling gap means treating cooling as the health necessity it has become, and building the shared knowledge to deliver it affordably and equitably.

References

1. KFF. Disparities in Access to Air Conditioning and Implications for Heat-Related Health Risks (2025). Heat-related deaths are likely undercounted; AC access tracks income and race; federal cooling-assistance and HUD heat guidance. https://www.kff.org/racial-equity-and-health-policy/disparities-in-access-to-air-conditioning-and-implications-for-heat-related-health-risks/

2. WHO Housing and Health Guidelines. High indoor temperatures. Geneva: WHO; 2018. Heat harms health via impaired cooling; children, older adults, and those with cardiovascular and pulmonary illness are most vulnerable. https://www.ncbi.nlm.nih.gov/books/NBK535285/

3. Center for Climate and Energy Solutions. Extreme Heat and Climate Change. Nighttime heat and humidity drive heat illness; risk concentrates in low-income communities. https://www.c2es.org/content/heat-waves-and-climate-change/

4. Unveiling hidden energy poverty using the energy equity gap. Nature Communications (2022). Low-income households in Arizona waited longer into dangerous heat before using AC than higher-income households. https://www.nature.com/articles/s41467-022-30146-5

5. Heating and Cooling Relief Act of 2025, Section-by-Section (Sen. Markey, Rep. Ansari). Heat-related deaths rising over 16% annually since 2016; cooling receives roughly 7% of LIHEAP funds. https://www.markey.senate.gov/download/heating-and-cooling-relief-act-section-by-section?download=1

6. WE ACT for Environmental Justice. Heat, Health & Equity. New York State cooling-assistance funding exhausted within days of summer opening in 2025. https://weact.org/programs/heat-health-equity/

7. EESI. Beating the Heat: A 2025 Heat Policy Agenda. Arizona recorded thousands of heat-related ER visits; bipartisan Congressional Extreme Heat Caucus. https://www.eesi.org/briefings/view/061725heat

8. World Resources Institute. Europe's Soaring Heat and the Great Air Conditioning Dilemma (2025). The tension between life-saving cooling and its energy and emissions costs. https://www.wri.org/insights/europes-heat-and-air-conditioning-dilemma