More extreme heat days are putting human health at risk in both the short and long term

Heat-related deaths may have climbed by more than 50% over 20 years

Between 2000 and 2009 one study suggests annual heat deaths averaged around 2,670, but between 2010 and 2020 that figure was likely more than 4,000. Researchers studied 54 million death records from the contiguous US and created mathematical models to arrive at these figures, noting that a combination of aging populations and climate change drove that increase.

Heatstroke can reprogram your DNA, putting survivors at risk of future health problems

Severe illness from extreme heat exposure can alter DNA through epigenetics—turning genes "on" or "off" to shape disease risk. These changes can place an organism at greater risk of future health complications—unlike the epigenetic changes produced by moderate, repeated heat exposures.

A third of Americans now live in wildfire risk zones

Climate change and human development into fire-prone regions have extended the wildfire season, with some areas experiencing fire conditions year-round. Extreme conditions, poor compensation, and exposure to carcinogens have complicated firefighter recruitment, further exacerbating wildfire risks.

67 US high school athletes died from exertional heatstroke between 1982 and 2022

Many of those deaths were from football specifically, where student athletes play in hot conditions while wearing heavy protective gear. Few states mandate heat guidelines for school athletes, and this article says that's of increasing concern with more high heat index days.

Extreme heat is neurologically impairing animals

Dog bites increase in summer, birds struggle to learn, and goats pick more fights. Scientists are unraveling new details about how heat impairs animals' neurological systems.

Schizophrenia increases heat death risks in several complex ways

Evidence shows that people with schizophrenia have an inherently harder time regulating internal body temperatures. They may also struggle to find safe shelter during extreme heat, and their prescribed antipsychotic medications often have dehydrating effects, collectively elevating the risk of heat-related illness and death, as illustrated by this article that focuses on the final days of Stephan Goodwin's life in 2022. (Some users may encounter a paywall.)

EXTREMA is a smart city system protecting residents from heat-related health risks

The mobile application is designed to protect citizens in select European cities from extreme temperatures by calculating the heat index at a specific location and providing personalized information to users. Municipal governments can also utilize it to inform emergency responses, such as determining when and where to open cooling centers.

Heat-related complications are of greater concern for distance runners than cardiac threats

Analysis of more than 130,000 runners in Tel Aviv events during a seven-year period indicated that the runners were 10 times more likely to experience heatstroke than serious cardiac problems. Scientists suggest that runners should take 10 to 14 days to acclimate to a hot climate before tackling a serious run.

City structures cause localized heat zones hotter than nearby rural areas

Urban materials like asphalt and concrete trap heat, while cities lack cooling features like trees and water. Due to hot runoff, urban streams can heat up by as much as 18°F more than forested streams.

What is a heat dome?

The world is seeing regular heat waves with multiple causes, including so-called "heat domes," a term rising in use in recent years. A heat dome occurs when the atmosphere traps hot ocean air like a lid or cap, creating stifling conditions and resulting in extended periods of heat. See an illustration of this phenomenon and read how it works with this brief explainer.

Extreme heat puts people at risk of developing kidney stones

It's essential to remain hydrated in summer weather to keep your body healthy, but one reason is to help dilute minerals that naturally build up if they aren't excreted in our water-fueled urine. Doctors recommend people generally drink 64 ounces of water a day and also eat foods with salt to help ward off dehydration.

Daylight Saving Time is linked to a rise in heart attacks and strokes

Losing an hour of sleep with seasonal time changes is not good for our health and it’s linked to risks for the first couple days of Daylight Saving Time, including a short-term rise in heart attacks and strokes. Scientists theorize these elevated risks are linked to the disruption to the body’s circadian rhythm.

Extreme weather conditions heighten cholera risks in settings like refugee camps

Runoff from sewage—exacerbated by situations like flooding or extreme rains—heightens this threat. Increasing temperatures also create the ideal conditions for the bacteria to reproduce, increasing transmission risks.

More than 20 mosquito-borne and tick-borne diseases are found in the US

Children, older adults, and people with compromised immune systems are at particular risk of poorer health outcomes from these diseases. But dog owners and outdoor enthusiasts are among those at particular risk of contracting these illnesses, which include Lyme disease, Zika, and the condition Alpha-gal Syndrome.

Rapid intensification can cause hurricanes to increase by two categories in 24 hours

Rapid intensification is a 35 mph or more increase in a hurricane's sustained wind speed within 24 hours. The phenomenon is expected to become more common, resulting in more storms becoming life-threatening faster than people can modify their preparations for the increased intensity.

Noise from data centers may disrupt wildlife and local residents

Individuals living where local ordinances have allowed data centers to be built next to residential areas have reported that the constant humming and vibrations from cooling systems have prevented them from sleeping and exposed them to chronic noise, which the American Public Health Association says can lead to cardiovascular disease and increased stress.

A map of extreme weather events and their links to climate change

To track how the evidence on this fast-moving topic is stacking up, Carbon Brief has mapped every extreme-weather attribution study published to date. Read more about the findings from the comprehensive analysis.

Climate change is disrupting maple syrup by shortening its production season

The number of unusually warm winter days in parts of Maine has increased significantly over the past few decades, stressing maple trees into shifted sap flows and leaving producers with less consistent outputs.

Greenhouse gas emissions from human activity accelerate recent global warming

These gases exacerbate the greenhouse effect—warming that results when the atmosphere traps heat radiating from Earth toward space. The most abundant atmospheric greenhouse gas is carbon dioxide, which is released from the burning of fossil fuels.

Why Hawaiians live longer

Hawaii has the longest life expectancy at birth out of all 50 states, according to the US Centers for Disease Control and Prevention. Key factors include strong healthcare, lots of sunlight, and active lifestyles.

Wind chill speeds up the loss of heat from the body

During cold weather conditions, strong winds against exposed skin can produce a sensation of temperature colder than the surrounding air temperature. The accelerated loss of body heat increases the risk of frostbite and hypothermia, with frostbite able to set in as quickly as five minutes.

Why Earth would become a more deadly environment without the ozone layer

The ozone layer blocks almost all of the sun's harmful, including dangerous UVC rays that can damage cells by breaking chemical bonds. Without it, rates of skin cancer, crop failures, oceanic die-offs, and widespread ecosystem collapse would increase significantly, making Earth largely uninhabitable.

Charting the rise of the American McMansion

US homes are growing larger and more luxurious, with Census Bureau data revealing a rise in four-bedroom houses equipped with air conditioning. Experts say the trend of elevated home prices is expected to continue.

Clinical burnout: prolonged exhaustion, mental distance, and persistent negative feelings

Burnout isn’t just stress—it’s a pervasive feeling of exhaustion that can start in the workplace and seep into everyday life. It causes feelings of dread and cynicism about work tasks. On top of emotional distress, there can be physical symptoms and a tendency towards addictive behavior.

America doesn't have enough estradiol patches for menopause and perimenopause demand

Fueled in part by the lifting of the FDA's black box warning about HRT risks, sales of estradiol patches in the US have shot upward. More than 142 million units of the patches were sold in 2025 versus 46.5 million in 2020. Suppliers are failing to keep up with demand—11 patch products were in short supply in early 2026. (Some users may experience a paywall.)

Poison ivy will likely become both larger and more resilient due to climate change.

11 people died from firework injuries in the US in 2024.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

View the ten deadliest tornadoes in US history.

Human-to-human transmission of hantavirus remains extremely rare, so the 2026 hantavirus cruise ship outbreak doesn't mean we're facing a COVID-style pandemic risk.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

About 12.5% of US adults experience a phobia in their lifetime, a diagnosis that hinges on the intense fear interfering with daily life and persisting for at least six months.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.