As record-breaking temperatures become more common across Texas and the United States, extreme heat is creating growing dangers for children, drivers, and pets, and making it more likely that you’ll need help from a car accident lawyer.
This study reveals our index of the states experiencing the most dangerously hot summer conditions; we’ll also examine how prolonged heat contributes to tragedies such as hot car deaths, plus heat-related illnesses, vehicle breakdowns, car accidents, and other preventable issues. With heat waves a key factor in a growing number of weather-related deaths in the U.S., heat preparedness is an increasingly important public safety issue.
Those dangers are not distributed evenly across the country. Our index shows where daytime heat, warm nights, long-term temperature patterns, unusual warmth, and population vulnerability combine to produce the greatest summer risk.
America’s Hottest States: Where Summer Heat Is Most Dangerous
According to our 2025 index, Florida ranks first for dangerous summer heat, earning an overall score of 84.5, narrowly ahead of Arizona (84.4) and Louisiana (84).
While Florida claims the top overall position thanks to persistently warm overnight temperatures (and an average summer minimum temperature of 73.8°F), Arizona recorded the nation’s highest daytime heat, averaging 95.7°F, and experienced the most extreme conditions.
Arizona’s grid cells averaged 33.5 summer days at or above 100°F and 6.2 days at or above 110°F, the highest diagnostic figures in the study. Texas ranked fourth (81.7) and was subject to the highest five-year average summer maximum temperature, 95.2°F, between 2021 and 2025.
All ten highest-ranked states are situated across the South and Sun Belt, highlighting the region’s persistent exposure to increasingly dangerous summer temperatures.
How the States Were Ranked
The Heat-Danger Index combines four measures of heat exposure with one measure of population vulnerability. Daytime heat accounts for 30% of each state’s score, nighttime heat for 20%, persistent five-summer heat for 20%, unusual 2025 warmth for 10%, and population vulnerability for 20%.
Each component was converted to a 0-to-100 state percentile before the five weighted values were combined. A higher score indicates greater comparative summer heat danger, not a predicted number of deaths, illnesses, crashes, or outages.
For contrast, here are the ten states we ranked as those featuring the lowest levels of summer heat risk.
Heat is Affecting an Increasing Number of Americans
Our ranking scores reflect a broader national warming trend. During July 2026, 23 states were placed under extreme heat warnings, with around 165 million people subject to major or extreme heat risk, and with temperatures reaching 115°F.
Across the contiguous United States, 2025 was the fourth-warmest year in 131 years of recorded temperatures. The average temperature during the year was 54.6°F: 2.6°F above the 20th-century average. The July average was 75.4°F, 1.8°F above the normal average July temperature, while the U.S. Climate Extremes Index measured conditions 58% above average, the 12th-highest value on record.
Several states experienced unprecedented warmth. Utah and Nevada logged their warmest years, while NOAA identified 54 counties across nine states (featuring over eight million people) that experienced record temperatures. Utah alone accounted for 24 of those counties. Even traditionally cooler regions are warming, with Alaska recording its ninth-warmest year across 101 years of recorded temperatures.
And twelve states (including Alabama, Georgia, and West Virginia) recorded their warmest average July minimum temperatures in 2025. North Carolina experienced its second-warmest July on record, while Georgia, West Virginia, and Maryland ranked third. Florida and South Carolina also recorded some of their warmest July periods.
One of the clearest indications of increasing heat risk is the rise in overnight temperatures, a factor that limits the body’s ability to recover after hot days. And those hot days are made worse by an increase in heat-wave weather patterns.
Increasing Heat Wave Frequency
Heat waves are now more frequent and longer-lasting than at any point on record. Major U.S. cities average around six heat waves each year, compared with roughly two a year during the 1960s. Cities highlighted by the EPA include Boston, Chicago, Dallas, Memphis, Miami, Phoenix, and Seattle.
The urban heat-wave season has lengthened to around 46 days since the 1960s, with individual heat waves lasting around four days.
Heat intensity also increases rapidly if we factor in humidity. At a temperature of 95°F and a humidity level of 50%, the heat index reaches approximately 107°F, while direct sunlight can increase the apparent temperature by up to 15°F.
As heat waves become more frequent and overnight relief disappears, one of the most immediate dangers develops inside parked vehicles.
The Rising Risk of Hot Car Deaths
States that feature high heat-danger scores are generally subject to elevated rates of child hot-car deaths relative to their child populations.
To illustrate this point, the top 10-ranked heat index states account for 531 of the 1,038 reported deaths of children in hot cars (51.2%) between 1998 and 2025. The five highest-index states alone account for 378 child hot-car deaths.
| № | State | Child Hot-Car Deaths |
|---|---|---|
| 1 | Florida | 115 |
| 2 | Arizona | 46 |
| 3 | Louisiana | 39 |
| 4 | Texas | 155 |
| 5 | Mississippi | 23 |
| 6 | Arkansas | 20 |
| 7 | Oklahoma | 31 |
| 8 | Alabama | 34 |
| 9 | South Carolina | 25 |
| 10 | Georgia | 43 |
For every 1 million children aged 14 and younger, the 10 highest heat-index states recorded an average of 33.7 hot-car deaths between 1998 and 2025.
To compare, the 10 lowest-index states averaged 8 child hot-car deaths, meaning the rate in the highest-risk group was just over four times higher.
| № | State | Child Hot-Car Deaths |
|---|---|---|
| 1 | Alaska | 0 |
| 2 | Minnesota | 8 |
| 3 | Wisconsin | 9 |
| 4 | Maine | 3 |
| 5 | Washington | 6 |
| 6 | New Hampshire | 0 |
| 7 | Hawaii | 5 |
| 8 | Vermont | 1 |
| 9 | North Dakota | 1 |
| 10 | Michigan | 11 |
For every 1 million children aged 14 and younger, the 10 highest heat-index states recorded an average of 33.7 hot-car deaths between 1998 and 2025.
To compare, the 10 lowest-index states averaged 8 child hot-car deaths, meaning the rate in the highest-risk group was just over four times higher.
| № | State | Child Hot-Car Deaths |
|---|---|---|
| 1 | Alaska | 0 |
| 2 | Minnesota | 8 |
| 3 | Wisconsin | 9 |
| 4 | Maine | 3 |
| 5 | Washington | 6 |
| 6 | New Hampshire | 0 |
| 7 | Hawaii | 5 |
| 8 | Vermont | 1 |
| 9 | North Dakota | 1 |
| 10 | Michigan | 11 |
NHTSA reports that 31 children died from vehicular heatstroke in 2025. NoHeatStroke.org recorded 16 deaths in 2026 through July 30, 2026; because the 2026 total continues to change, it should be checked again immediately before publication.
The long-term average is 37 deaths a year, though 2018 and 2019 both reached a modern record (53 deaths). Between 1998 and 2025, the leading cause was a caregiver forgetting about a child, a factor that accounted for 52.9% of cases (531 deaths).
Children getting into a hot car of their own accord accounted for 23.8% of cases (248 deaths), while children knowingly left in vehicles represented 21.9% (228 deaths). Unknown circumstances made up the remaining 1.3% (14 deaths).
Children under the age of 2 account for 54% of children who die in hot cars, with the average age of child victims 27 months (according to the 2026 NoHeatStroke profile).
Vehicle temperatures can rise at a shocking rate on hot days. If the outside temperature is 72°F, car interiors can reach 117°F within an hour, with 80% of that temperature increase occurring during the first half hour. After an hour, vehicle interiors average about 40°F hotter than outside temperatures (between 72°F and 96°F).
That said, hot-car deaths occur during every month of the year, even when outside temperatures are as low as 13°F: clearly, risk isn’t just a matter of extreme summer heat.
Risks to pets are also significant. PETA’s 2026 tracking data confirms 60 animal heat deaths and 412 animal rescues up to July 24. In 2025, the PETA tracker recorded 151 animal heat deaths and 365 rescues; additional data suggested that most incidents of this type are not reported. Kids and Car Safety data similarly suggests that hot-car cases involving children under 14 are likely significantly under-reported.
Hot vehicles are one preventable consequence of extreme temperatures, but the wider health burden reaches workers, older adults, pregnant women, and entire healthcare systems.
An American Heat Emergency: Those Most at Risk
Extreme heat is an increasingly significant public health issue that affects vulnerable people, outdoor workers, and healthcare systems.
While measured heat accounts for an 80% score weight regarding our heat index, the remaining 20% reflects population vulnerability across young children, older adults, and workers in outdoor or physically demanding occupations.
By this criterion, South Dakota earns the highest vulnerability score (76.2), although its comparatively mild climate places it 30th in the overall rankings. Individual demographic factors also highlight differing risks across states.
Utah has the nation’s highest proportion of children under five (6.5%); Maine has the oldest population in the U.S., with nearly one in four of its residents aged 65 or older; and Wyoming has the highest share of outdoor workers (14.4%), meaning a significant number of its residents face severe occupational exposure to dangerous heat.
The ten highest-ranked heat-risk states average a vulnerability score of 57.6, compared with 50.6 among the ten lowest-ranked states: this shows how demographic exposure contributes to the overall rankings and can compound the health consequences of extreme temperatures.
Heat-Related Illness Is Rising
The CDC recorded 119,605 heat-related emergency department visits in 2023, 92% of which occurred between May and September. Visits more than tripled during the hottest months; there were an average of 303 heat-related visits per 100,000 emergency department visits in July and August, compared with 97 per 100,000 during May, June, and September.
Heat illness disproportionately affects working-age adults and men. Men recorded emergency department visit rates more than twice those of women (271 for men, compared to 104 for women per 100,000 visits), while adults aged between 18 and 64 were particularly susceptible.
There were also notable geographic differences: Arkansas, Louisiana, New Mexico, Oklahoma, and Texas reported rates nearly ten times higher than New York and New Jersey.
Heat-Related Deaths Primarily Occur in the West and South
CDC mortality data confirms that Arizona recorded both the highest number and the highest population-adjusted rate of heat-related deaths. By rate, Nevada, Oregon, and Washington followed. Louisiana was the highest-ranked Southern state, while California, Texas, and Florida also recorded substantial fatality counts.
Cities also carry a significant heat-related fatality burden. New York City figures suggest that heat contributes to around 500 deaths every year, although only a small proportion are directly attributed as such.
Preliminary 2025 data identified 21 direct heat deaths (including 19 during June alone), highlighting how much extreme heat can affect mortality during prolonged hot periods.
The Extreme Risk Outdoor Workers Face
Workers in construction, agriculture, landscaping, manufacturing, postal services, and other physically demanding outdoor occupations are subject to some of the highest heat illness rates.
Federal data confirms there were 48 occupational heat deaths during 2024, including 40 occurring outdoors, while construction accounted for 24 of the 48 occupational heat deaths. Between 1992 and 2022, the Bureau of Labor Statistics recorded 1,042 worker heat deaths; annual fatalities have increased during the most recent decade.
Between 2011 and 2020, nearly 34,000 heat illnesses involved time away from work. OSHA investigations between 2017 and 2022 found 625 hospitalisations, 218 additional serious illnesses, and 211 worker deaths, with construction consistently representing the highest-risk industry.
Although no comprehensive state ranking exists for all occupational heat deaths, construction data identifies Arkansas, Oklahoma, Louisiana, Texas, Illinois, and Arizona among the states with the highest documented construction-worker heat fatality rates.
The Groups That Face Extreme Health Risks
Young children, older adults, and pregnant women are particularly vulnerable to heat-related death and illness. That’s because they regulate their body temperature less effectively than other age groups or suffer from underlying health conditions that exacerbate their susceptibility.
The CDC warns that just one day of extreme heat may increase pregnancy risks, including preterm birth, stillbirth, and low birthweight. One federal study found exposure during weeks 15 to 21 of pregnancy was linked to an 18% higher risk of late preterm delivery, while sustained heat exposure during a pregnancy was associated with adverse birth-outcome risks up to 21% higher.
Heat can also compromise the effectiveness of some essential medications and medical devices. The CDC notes that some diuretics, anticholinergic medications, and psychotropic drugs increase a taker’s sensitivity to heat, while high temperatures can damage inhalers, epinephrine auto-injectors, and insulin if they’re not suitably stored.
Older Adults Need Extra Protection
Older adults are especially vulnerable during prolonged heat events, particularly residents in long-term care settings.
A 2026 study of 73,578 deaths across 615 Ontario nursing homes found significantly higher mortality during periods of extreme heat in facilities that lacked air conditioning. The installation of air conditioning was estimated to have prevented 33 deaths, reinforcing the importance of heat mitigation in residential care settings.
Florida now pre-empts such risks as part of state policy: Florida residential homes must now maintain backup power capable of operating for at least 96 hours and keeping resident-occupied areas at or below 81°F during emergencies.
Beyond the direct health burden, prolonged heat also strains the roads, vehicles, power systems, and emergency resources that communities rely on.
When Heat Severely Disrupts Daily Life
Extreme heat puts growing pressure on energy systems, transport infrastructure, and public safety. Grid reliability varies among high-heat states: in 2024, South Carolina recorded the highest all-event SAIDI (system average interruption duration index) among the heat index’s top 10 states (3,136.5 customer interruption minutes), while Arizona recorded the lowest at 87.5 minutes, confirming that heat exposure and grid reliability are not interchangeable.
Across the U.S. in 2024, the average customer experienced 611.3 interruption minutes (when major events were included), compared with 126 minutes not featuring major events.
Heat-driven electricity demand has reached record levels. ERCOT set a Texas electricity-demand record of 91,089 megawatts on July 22, 2026, exceeding the previous 85,508-megawatt record (set in August 2023) by 6.5%. Texas demand climbed steadily during the 2026 heat season, reaching 77,822 MW on May 29, 82,772 MW on June 18, 83,198 MW on July 6, 87,403 MW on July 21, and 91,089 MW on July 22.
In the PJM region, a July 2026 DOE order cited temperatures of 95°F or higher across the region, temperatures above 100°F in three utility zones, and projected demand peaks of 159,563 and 162,860 megawatts.
Under conditions of extreme demand, outages, and heat-related generator derating, PJM’s expected reserve margin could potentially drop from 26% to 3.8%. On July 2, 2026, DOE authorized specified Carolinas generators to exceed normal output limits until July 6 to reduce the likelihood of heat-related blackouts.
Extreme heat also affects transport systems. The AAA reports that high temperatures can reduce a typical three- to five-year vehicle battery lifespan by at least two years. Additionally, pavement temperatures can reach 150°F, increasing the risk of tire damage and blowouts.
Texas’s 2025 transportation resilience plan uncovered the fact that over half of the state’s roadways have moderate or high vulnerability to extreme heat and wildfire, with TxDOT identifying pavement rutting, buckling, and cracking as major heat-related risks. Wildfire, smoke, and low visibility can also lead to road closures and detours.
For drivers, these conditions can create overlapping risks: damaged tires, weakened batteries, buckled pavement, roadside breakdowns, reduced visibility, and longer detours during already dangerous temperatures.
State readiness for heat-related events is often key, but how well prepared are high-risk states?
Staying Safe in Record Heat: Which States Are Best Prepared?
Some states have responded to increasingly dangerous hot summer periods with a combination of heat action plans, cooling resources, public alerts, worker protections, emergency programs, and community resilience measures. Yet protections remain uneven across the highest heat-risk states.
In fact, none of the ten highest-ranked heat-index states has introduced a broad, enforceable worker heat standard. States with comprehensive heat standards in place include California, Maryland, Minnesota, Nevada, Oregon, and Washington, while Colorado has an enforceable rule that’s limited to agricultural workers, and Virginia plans to introduce an enforceable worker heat standard by May 1, 2028.
California features one of the strongest suites of heat protections: indoor heat rules that generally activate at 82°F and require water; cooling areas; training schemes; and heat-illness response procedures. Its outdoor rules mandate shade for working conditions that exceed temperatures of 80°F, additional protections beyond 95°F in specific roles, and enough water for workers to drink 32 ounces per hour during sweltering weather.
Animal heat protections are also inconsistent. In 2026, only four of the top 10 heat-index states (Arizona, Florida, Louisiana, and Georgia) carry parked-animal laws. Louisiana and Arizona are the only two states in the heat-index top five that also have parked-animal laws and rank among the five states with the highest child hot-car death rates.
Texas law provides conditional civil immunity to a person who forcibly enters a vehicle to rescue a vulnerable individual, including a child younger than seven, when the person reasonably believes entry is necessary to prevent imminent harm, contacts law enforcement or 911, uses no more force than necessary, and remains nearby. However, Chapter 92A does not extend that protection to rescuing an animal from a hot vehicle.
Energy affordability and community resilience programs provide extra support during extreme heat. Minnesota prevents involuntary residential utility disconnections in affected counties during National Weather Service excessive-heat watches, advisories, or warnings.
Overall, less than half (19, plus the District of Columbia) of U.S. states provide some form of extreme-heat utility disconnection protection. The Low Income Home Energy Assistance Program (LIHEAP) served 5.9 million low-income households in federal year 2024 across all assistance categories. Heat-specific support in the federal year 2023 included 751,000 homes that received cooling assistance and 106,000 that received summer-crisis assistance.
There is also an increasing number of local resilience strategies. Dallas’s Urban Forest Master Plan reports that trees can reduce local temperatures by up to 15°F, making urban greening a measurable approach to lowering neighborhood heat risk.
Utah and Nevada logged their warmest years, while NOAA identified 54 counties across nine states (featuring over eight million people) that experienced record temperatures
Extreme Heat: Necessary Measures
Extreme heat is a growing public safety threat across the U.S., with the highest risks concentrated in the South and Sun Belt. This study confirms that hotter states face increased impacts on health, as well as threats to children and pets in vehicles, workers, infrastructure, power systems, and transportation; as things stand, preparedness measures remain inconsistent.
Florida, Arizona, and Louisiana lead the Heat-Danger Index, while Texas ranks fourth and combines persistent heat exposure with gaps in worker and parked-animal protections.
The most heat-exposed states are not always the best protected. Extreme heat amplifies risks across communities, and stronger prevention measures, worker protections, emergency planning, and resilience investments are needed to reduce avoidable harm as the problem worsens.
At Aulsbrook Car & Truck Wreck Injury Lawyers, we don’t just bark, we bite, and we’re ready to take on your case. Fill out our consultation form for a free case evaluation, and let’s get started today!
Methodology
Texas Law Dog created a 50-state Heat-Danger Index using the latest complete summer data available for 2025. Each state received a score from 0 to 100 across five components: average summer maximum temperature in 2025 (30%), average summer minimum temperature in 2025 (20%), average summer maximum temperature from 2021 through 2025 (20%), the 2025 maximum-temperature anomaly compared with the 20th-century average (10%), and population vulnerability (20%).
The vulnerability component averages state percentile rankings for three groups that may face greater heat exposure or sensitivity: children younger than 5, adults aged 65 and older, and workers in natural resources, construction, and maintenance occupations.
Each scored measure was converted into a state percentile, with higher values representing greater heat exposure or vulnerability. The five weighted component scores were then combined to produce the final Heat-Danger Index score.
Average grid-cell days at or above 90°F, 100°F, and 110°F, child hot-car deaths from 1998 through 2025, and deaths per 1 million children aged 14 and younger were included as contextual diagnostics. These measures did not affect the final rankings. Comparable grid-cell day counts were unavailable for Alaska and Hawaii, but those missing diagnostic values did not affect either state’s score.
Temperature data came from NOAA and the National Centers for Environmental Information. Population-age measures came from the U.S. Census Bureau, occupational measures came from federal labor data, and child hot-car totals came from NoHeatStroke.org.
Figures were rounded to one decimal place, so displayed component values may produce minor rounding differences. The index identifies comparative risk and does not establish that heat exposure alone caused any reported illness, death, outage, or vehicle incident.
