Health Insurance
Heat-Related Deaths Up 56% Between 2018 and 2021, Provisional Data Shows
Extreme heat feels like the new normal for many in the U.S., and it’s only getting hotter. Last July was the hottest month ever recorded, according to the National Oceanic and Atmospheric Administration (NOAA). In the U.S., where July is regularly the hottest month of the year, many states saw new high temperatures.
As global temperatures continue to climb, heat-related deaths are also up. Amid last year’s record-shattering temperature spikes, early estimates from the Centers for Disease Control and Prevention (CDC) indicate that heat deaths jumped 56% between 2018 and 2021.
This latest ValuePenguin study examines the CDC’s Provisional Mortality Statistics data to provide deeper context into the rate of heat-related deaths from 2018 to 2021. We’ll look at which states have the most deaths relative to their population, and the ages and races of those who died from heat-related complications.
- Key findings
- Amid increasingly sweltering summers, Nevada has the highest rate of heat-related deaths
- Michigan has the fewest heat-related deaths relative to the population
- Higher rate of older Americans die from heat-related complications
- American Indians, Alaska Natives have the highest death rates
- How to keep cool in the heat
- Methodology
Key findings
- Heat was a contributing factor in 1,577 U.S. deaths in 2021, according to provisional data. That’s a 56% jump from 1,012 in 2018.
- Heat-related deaths are most common in Nevada and Arizona. Between 2018 and 2021, 571 people in Nevada and 1,298 people in Arizona died where heat was among the causes of death. That’s 4.54 and 4.46 deaths per 100,000 residents, respectively, over that period — far higher than the U.S. average over the same period of 0.35 per 100,000 residents.
- Among states with qualified heat-related deaths in this period, they’re least common in Michigan and Colorado. In the same period, 11 people each died in these states, which equates to 0.03 and 0.05 deaths per 100,000 residents, respectively.
- Older Americans face higher heat-related death rates than younger Americans. The age group most vulnerable are Americans 85 and older, where heat is a cause in 0.98 annual deaths per 100,000 residents. For Americans 5 to 14, the group with the lowest rate, that figure is 0.01 per 100,000 (27 deaths over the four years).
- Among races, American Indians and Alaska Natives die at a higher rate. For these two races, the heat-related death rate is 0.71 per 100,000 residents annually. That compares to 0.32 and 0.29 per 100,000, respectively, among Black and white residents.
What’s considered a heat-related death?
The CDC uses death certificates as a basis for its Provisional Mortality Statistics. To estimate the number of heat-related deaths, ValuePenguin researchers analyzed the data to determine the number of deaths where heat was listed as an underlying cause. Specifically, researchers examined the following scenarios listed as causes of death:
- Heatstroke and sunstroke
- Heat syncope
- Heat cramp
- Heat exhaustion, anhidrotic
- Heat exhaustion due to salt depletion
- Heat exhaustion, unspecified
- Heat fatigue, transient
- Heat edema
- Other effects of heat and light
- Effect of heat and light, unspecified
- Exposure to excessive natural heat (hyperthermia)
While we looked at data from 2018 through 2021, the 2021 data is provisional. That means the 2021 data — an early estimate — hasn’t been fully reviewed by the National Center for Health Statistics.
Amid increasingly sweltering summers, Nevada has the highest rate of heat-related deaths
There were 1,012 heat-related deaths in the U.S. in 2018, which jumped to 1,577 in 2021. In the time frame analyzed, the only year that didn’t see a year-over-year increase was 2019.
Heat-related deaths (by the year) | |
|---|---|
| 2018 | 1,012 |
| 2019 | 911 |
| 2020 | 1,156 |
| 2021 | 1,577 |
Source: ValuePenguin analysis of Centers for Disease Control and Prevention (CDC) Provisional Mortality Statistics data
While heat-related deaths were generally on the rise, the death rate varied widely by state. In Nevada, which had the highest overall death rate, there were 4.54 deaths per 100,000 residents from 2018 to 2021 — far above almost every other state analyzed. Only one state — Arizona — had a similarly high death rate. But every other state with qualified heat deaths during this period saw less than 1.00 heat-related deaths per 100,000 residents — which makes sense with a national death rate over the four years of 0.35 per 100,000 residents.
Most heat-related deaths relative to population
Rank | State | Deaths | Annualized rate per 100,000 residents |
|---|---|---|---|
| 1 | Nevada | 571 | 4.54 |
| 2 | Arizona | 1,298 | 4.46 |
| 3 | Oregon | 132 | 0.78 |
| 4 | Washington | 162 | 0.52 |
| 5 | New Mexico | 42 | 0.50 |
Source: ValuePenguin analysis of CDC Provisional Mortality Statistics data
These findings come amid a drastic increase in the number and severity of days with extremely high temperatures. In the West and Southwest, where extreme heat events are particularly common, there hasn’t been much relief in three of the past four years, according to the NOAA’s Climate Extremes Index.
For context, Nevada recorded 111 extreme heat events above 100 degrees Fahrenheit in 2018 — a number that jumped to 130 in 2020, according to the CDC’s National Environmental Public Health Tracking Network. In Arizona, extreme heat events at the same temperature jumped from 538 in 2018 to 647 in 2020.
While the 2021 data isn’t available yet, a record-breaking heat wave swept the Southwest U.S. last June. Eight states had their hottest June on record, according to the NOAA — including Nevada and Arizona, which may also help explain the disparity in death rates.
States known for mild summers hit harder in 2021
The Southwest wasn’t the only region with a record-breaking heat wave last June. In the Pacific Northwest, a region where summers are historically so mild that many buildings aren’t equipped with air conditioning, a four-day heat wave may account for the rate of heat-related deaths in the region.
Across all four years analyzed, many Pacific Northwestern states saw their only heat-related deaths during 2021.
In the Provisional Mortality Statistics data, nine or fewer deaths in a year are suppressed to protect confidentiality. We assigned these years as having zero deaths because there’s no way to differentiate between years when there were no deaths in a particular state and years when the data was suppressed. So it’s possible that a state had up to nine heat-related deaths in a given year when we’re saying it didn’t have any.
In Oregon, which had the third-highest death rate of any state analyzed, all 132 heat-related deaths occurred in 2021. Other states in the Pacific Northwest that had their only deaths in 2021 include:
- Washington: 162 heat-related deaths
- Idaho: 10 heat-related deaths
During the heat wave, temperatures reached 119 degrees in Washington, while Oregon saw temperatures hit 118 degrees, according to the NOAA. With less access to air conditioning than in most other states, many residents in this typically temperate region were likely unable to cool down.
Michigan has the fewest heat-related deaths relative to the population
In Michigan, the state with the lowest rate of annual heat-related deaths, 11 people died from a heat-related injury — a rate of 0.03 per 100,000 residents. Colorado ranked second, with 0.05 deaths per 100,000 residents annually.
All five states with the lowest rates of heat-related deaths had less than 0.10 annual deaths per 100,000 residents:
Fewest heat-related deaths relative to population
Rank | State | Deaths | Annualized rate per 100,000 residents |
|---|---|---|---|
| 1 | Michigan | 11 | 0.03 |
| 2 | Colorado | 11 | 0.05 |
| 3 | Wisconsin | 13 | 0.06 |
| 4 | Kentucky | 10 | 0.06 |
| 5 | New York | 71 | 0.09 |
Source: ValuePenguin analysis of CDC Provisional Mortality Statistics data
Still, the states with the lowest rates of heat-related deaths weren't exempt from last year’s volatile and unpredictable summer conditions. Both Michigan and Colorado only recorded heat deaths in the 2021 provisional data. (Remember: It’s possible that both states had up to nine deaths in the other three years examined — 2018 to 2020 — but that data would have been suppressed.)
Full rankings
Heat-related deaths relative to population
Rank | State | Deaths | Annualized rate per 100,000 residents |
|---|---|---|---|
| 1 | Nevada | 571 | 4.54 |
| 2 | Arizona | 1,298 | 4.46 |
| 3 | Oregon | 132 | 0.78 |
| 4 | Washington | 162 | 0.52 |
| 5 | New Mexico | 42 | 0.50 |
| 6 | Louisiana | 85 | 0.46 |
| 7 | Arkansas | 54 | 0.45 |
| 8 | Maryland | 104 | 0.42 |
| 9 | Texas | 378 | 0.32 |
| 10 | Mississippi | 36 | 0.31 |
| 11 | Alabama | 60 | 0.30 |
| 12 | Oklahoma | 46 | 0.29 |
Source: ValuePenguin analysis of CDC Provisional Mortality Statistics data. States not listed had nine or fewer deaths across each of the four years analyzed.
Higher rate of older Americans die from heat-related complications
While older Americans generally experience more heat-related deaths than younger age groups, the figure is highest among Americans 85 and older at an annual rate of 0.98 deaths per 100,000 residents between 2018 and 2021.
Take a look at the figures:
Heat-related deaths relative to population (by age)
Age group | Deaths | Annualized rate per 100,000 residents |
|---|---|---|
| Less than 1 | 51 | 0.27 |
| 1 to 4 | 139 | 0.18 |
| 5 to 14 | 27 | 0.01 |
| 15 to 24 | 142 | 0.07 |
| 25 to 34 | 365 | 0.16 |
| 35 to 44 | 526 | 0.25 |
| 45 to 54 | 667 | 0.33 |
| 55 to 64 | 932 | 0.44 |
| 65 to 74 | 878 | 0.55 |
| 75 to 84 | 620 | 0.77 |
| 85 and older | 323 | 0.98 |
Source: ValuePenguin analysis of CDC Provisional Mortality Statistics data
Infants experience more heat-related deaths than similar age groups. They’re more at risk because they can’t adjust to sudden temperature changes as fast as other age groups, according to the CDC. This may also happen because of illnesses that affect their ability to regulate body temperature. For older Americans, the medications they take may interfere with their body temperatures.
For Americans younger than 1, the annual death rate is 0.27 per 100,000 residents. The death rate is lowest for Americans who are 5 to 14 years old at 0.01 (27 deaths). From here, the death rate steadily increases with age.
American Indians, Alaska Natives have the highest death rates of any race
There are also notable disparities in the death rate among races. The annual death rate between 2018 and 2021 is highest among American Indians and Alaska Natives at 0.71 per 100,000 residents — more than twice the rate of Black and white residents, whose death rates are 0.32 and 0.29 per 100,000 residents, respectively.
Heat-related deaths relative to population (by race)
Race | Deaths | Annualized rate per 100,000 residents |
|---|---|---|
| American Indian or Alaska Native | 151 | 0.71 |
| Asian | 90 | 0.09 |
| Black or African American | 716 | 0.32 |
| White | 3,636 | 0.29 |
| More than one race | 72 | 0.15 |
Source: ValuePenguin analysis of CDC Provisional Mortality Statistics data
Social, economic and health disparities likely play a role in the differences in death rates here. Historic housing policies have pushed many low-income people and minority groups into urban neighborhoods. The concentrated development in these densely populated areas often creates an "island" of heat not seen in other areas, which increases the risk of heat-related death.
Lack of access to health care may also play a role. Robin Townsend, a ValuePenguin technical writer whose focus is health and life insurance, says this is particularly true among uninsured people. While heat-related deaths are largely preventable, Townsend says people who don’t have health insurance may feel too dissuaded by high health care costs to seek help when they begin to exhibit symptoms.
"Heat-related illness can progress rapidly, so prompt medical care is key to preventing a heat-related death," Townsend says. "With summers getting hotter, providing better access to health insurance will be critical to getting people the care they need — and can ultimately reduce the number of heat-related deaths in the U.S."
How to keep cool in the heat
As summer approaches, check your health insurance plan to ensure you feel confident seeking help for heat-related illnesses — and compare quotes to find the plan that best fits your needs. Additionally, consider these tips from the CDC to reduce your risk of heat-related illness:
- Stay cool. Choose lightweight clothing and stay in air-conditioned places as much as possible. Additionally, try to limit your time outdoors to when the weather is coolest, and take breaks in the shade whenever possible.
- Stay hydrated. Drink more fluids, regardless of your activity level. Electrolyte replacement drinks are particularly recommended, but avoid soda or alcoholic drinks, which can further dehydrate you.
- Stay informed. Keep track of the extreme heat alerts in your area. If you don’t have access to air conditioning, learn about any local cooling shelters. Additionally, learn the symptoms of heat-related illnesses and monitor those at higher risk.
Methodology
ValuePenguin researchers analyzed Centers for Disease Control and Prevention (CDC) Provisional Mortality Statistics data to find the states where heat-related reasons were listed as one of the causes of death. We then estimated deaths per 100,000 residents.
Specifically, researchers examined the following scenarios listed as causes of death:
- Heatstroke and sunstroke
- Heat syncope
- Heat cramp
- Heat exhaustion, anhidrotic
- Heat exhaustion due to salt depletion
- Heat exhaustion, unspecified
- Heat fatigue, transient
- Heat edema
- Other effects of heat and light
- Effect of heat and light, unspecified
- Exposure to excessive natural heat (hyperthermia)
The Provisional Mortality Statistics data is based on death certificates for U.S. residents. While we looked at data from 2018 through 2021, the 2021 data is provisional. That means the 2021 data — an early estimate — hasn’t been fully reviewed by the National Center for Health Statistics.
Also, statistics by state for a given year are suppressed when there are zero to nine deaths in a given year to maintain confidentiality. We used "zero" to represent those years when data was suppressed.