Health
When heat waves turns deadly: How extreme temperatures affect the human body
As temperatures and humidity soar outside, what’s happening inside the human body can become a life-or-death battle decided by just a few degrees.
The critical danger point outdoors for illness and death from relentless heat is several degrees lower than experts once thought, say researchers who put people in hot boxes to see what happens to them.
With much of the United States, Mexico, India and the Middle East suffering through blistering heat waves, worsened by climate change, several doctors, physiologists and other experts explained to The Associated Press what happens to the human body in such heat.
HEAT WAVE LEAVES AT LEAST 125 DEAD IN MEXICO
Heat waves can raise your body temperature
The body’s resting core temperature is typically about 98.6 degrees Fahrenheit.
That’s only 7 degrees away from catastrophe in the form of heatstroke, said Ollie Jay, a professor of heat and health at the University of Sydney in Australia, where he runs the thermoergonomics laboratory.
Dr. Neil Gandhi, emergency medicine director at Houston Methodist Hospital, said during heat waves anyone who comes in with a fever of 102 or higher and no clear source of infection will be looked at for heat exhaustion or the more severe heatstroke.
A man pours cold water onto his head to cool off on a sweltering hot day in the Mediterranean Sea in Beirut, Lebanon, on July 16, 2023. As temperatures and humidity soar, what’s happening inside the human body can become a life-or-death battle decided by just a few degrees. (AP Photo/Hassan Ammar, File)
“We routinely will see core temperatures greater than 104, 105 degrees during some of the heat episodes,” Gandhi said. Another degree or three and such a patient is at high risk of death, he said.
How heat kills
Heat kills in three main ways, Jay said. The usual first suspect is heatstroke — critical increases in body temperature that cause organs to fail.
When inner body temperature gets too hot, the body redirects blood flow toward the skin to cool down, Jay said. But that diverts blood and oxygen away from the stomach and intestines, and can allow toxins normally confined to the gut area to leak into circulation.
“That sets off a cascade of effects,” Jay said. “Clotting around the body and multiple organ failure and, ultimately, death.”
But the bigger killer in heat is the strain on the heart, especially for people who have cardiovascular disease, Jay said.
It again starts with blood rushing to the skin to help shed core heat. That causes blood pressure to drop. The heart responds by trying to pump more blood to keep you from passing out.
“You’re asking the heart to do a lot more work than it usually has to do,” Jay said. For someone with a heart condition “it’s like running for a bus with dodgy (hamstring). Something’s going to give.”
7 WAYS TO STAY SAFE IN THIS SUMMER’S SCORCHING HEAT
The third main way is dangerous dehydration. As people sweat, they lose liquids to a point that can severely stress kidneys, Jay said.
Many people may not realize their danger, Houston’s Gandhi said.
Dehydration can progress into shock, causing organs to shut down from lack of blood, oxygen and nutrients, leading to seizures and death, said Dr. Renee Salas, a Harvard University professor of public health and an emergency room physician at Massachusetts General Hospital.
“Dehydration can be very dangerous and even deadly for everyone if it gets bad enough — but it is especially dangerous for those with medical conditions and on certain medications,” Salas said.
Dehydration also reduces blood flow and magnifies cardiac problems, Jay said.
Intense heat can ‘fry’ your brain
Heat also affects the brain. It can cause a person to have confusion, or trouble thinking, several doctors said.
“One of the first symptoms you’re getting into trouble with the heat is if you get confused,” said University of Washington public health and climate professor Kris Ebi. That’s little help as a symptom because the person suffering from the heat is unlikely to recognize it, she said. And it becomes a bigger problem as people age.
One of the classic definitions of heat stroke is a core body temperature of 104 degrees “coupled with cognitive dysfunction,” said Pennsylvania State University physiology professor W. Larry Kenney.
Heat and humidity are a dangerous duo
Some scientists use a complicated outside temperature measurement called wet bulb globe temperature, which takes into account humidity, solar radiation and wind. In the past, it was thought that a wet-bulb reading of 95 Fahrenheit was the point when the body started having trouble, said Kenney, who also runs a hot box lab and has done nearly 600 tests with volunteers.
His tests show the wet-bulb danger point is closer to 87. That’s a figure that has started to appear in the Middle East, he said.
And that’s just for young healthy people. For older people, the danger point is a wet bulb temperature of 82, he said.
“Humid heat waves kill a lot more people than dry heat waves,” Kenney said.
When Kenney tested young and old people in dry heat, young volunteers could function until 125.6 degrees, while the elderly had to stop at 109.4. With high or moderate humidity, the people could not function at nearly as high a temperature, he said.
“Humidity impacts the ability of sweat to evaporate,” Jay said.
How to cool down heat exhaustion patients
Heatstroke is an emergency, and medical workers try to cool a victim down within 30 minutes, Salas said.
The best way: Cold water immersion. Basically, “you drop them in a water bucket,” Salas said.
But those aren’t always around. So emergency rooms pump patients with cool fluids intravenously, spray them with misters, put ice packs in armpits and groins and place them on a chilling mat with cold water running inside it.
Sometimes it doesn’t work.
“We call it the silent killer because it’s not this kind of visually dramatic event,” Jay said. “It’s insidious. It’s hidden.”
NEWYou can now listen to Fox News articles!
Older adults identified as “super movers” are about half as likely to develop cognitive impairment than their peers.
That’s according to a recent study led by Stony Brook Medicine in New York, which evaluated the cognitive function of 4,000 adults 80 and over who participated in multiple aging and longevity studies over several years.
Among this group, 6% to 10% were classified as super movers, which means they walk at a much faster pace than others of the same age and gender — at speeds comparable to people three decades younger.
COMMON VITAMIN MAY INFLUENCE BRAIN AGING IN WAYS SCIENTISTS DIDN’T EXPECT
The super movers were found to have about half the risk of cognitive decline compared to seniors with typical gait speed.
The findings were published in the journal Neurology on June 16.
Older adults identified as “super movers” are about half as likely to develop cognitive impairment than their peers. (iStock)
“The study reinforces that mobility and brain health are closely connected,” lead study author Dr. Joe Verghese, MD, neurologist at Stony Brook Medicine, told Fox News Digital. “This suggests that preserving mobility may be an important marker of healthy brain aging and resilience.”
‘LONGEVITY GENE’ MAY PROTECT THE BRAIN FROM ALZHEIMER’S BY BOOSTING DNA REPAIR, STUDY FINDS
The most intriguing finding, according to Verghese, was that super movers maintained cognitive function despite having similar dementia-related brain changes as their peers.
In postmortem brain analysis, there was no difference in dementia-related pathologies between the super movers and the slower walkers, the study stated.
TEST YOURSELF WITH OUR LATEST LIFESTYLE QUIZ
“This suggests they may possess resilience mechanisms that help preserve brain function even in the presence of age-related changes,” he said. “Understanding these resilience factors could lead to new strategies for promoting healthy brain aging.”
As the study was observational, there were some limitations, and it does not prove that walking faster prevents dementia, the researchers noted.
Super movers were found to have about half the risk of cognitive decline compared to seniors with typical gait speed. (iStock)
“Other factors, such as cardiovascular health, physical fitness or genetics, may also contribute to both faster walking and better cognitive outcomes,” Verghese said.
CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER
This study adds to growing evidence that what’s good for the heart and muscles also benefits the brain, he noted, adding that “staying physically active remains one of the most effective, evidence-based ways to support healthy aging.”
“Walking speed is best viewed as a marker of overall health, not a treatment.”
“The broader message is that physical activity is important at any age,” Verghese said. “Walking is an easy step-up point because you don’t need any special equipment. You can do it inside or outdoors, and you can do it on a regular basis. You can walk with a dog, you can walk with a friend.”
Any activity is beneficial if it’s done regularly and with the right intensity, he added.
CLICK HERE FOR MORE HEALTH STORIES
Rather than just trying to walk faster, the neurologist recommends that seniors focus on maintaining mobility through regular physical activity, strength training, balance exercises and good cardiovascular health.
“Walking speed is best viewed as a marker of overall health, not a treatment,” Verghese noted.
Major public health guidelines from the CDC and U.S. Physical Activity Guidelines recommend at least 150 minutes of moderate-intensity aerobic activity each week, such as brisk walking.
Major public health guidelines from the CDC and U.S. Physical Activity Guidelines recommend at least 150 minutes of moderate-intensity aerobic activity each week, such as brisk walking. (iStock)
This can be achieved by walking 30 minutes a day, five days a week, or about 20 to 25 minutes most days. Another option is to engage in shorter sessions that add up over the day.
CLICK HERE TO DOWNLOAD THE FOX NEWS APP
“You have to do it within your health limitations and medical conditions,” Verghese advised. “So if there are any medical concerns, I would get your physician to clear you before starting exercise.” The good thing about walking, he added, is that you can start at a slow pace and then gradually build up to a brisker pace.
“And then adding on strength and balance training, whatever age you are, I think is also important.”
Use left and right arrow keys to navigate between menu items.
Use escape to exit the menu.
Sign Up
Create a free account to access exclusive content, play games, solve puzzles, test your pop-culture knowledge and receive special offers.
Already have an account? Login
Health
Dr Oz warns Medicare scammers are stealing billions — and your personal information could be next
NEWYou can now listen to Fox News articles!
Washington, D.C. – Medicare fraud is a multibillion-dollar problem that government officials say threatens both taxpayer dollars and Americans’ personal identities.
In a July 6 interview with Fox News Digital at the Great American State Fair in Washington, D.C., Dr. Mehmet Oz warned that every dollar stolen through Medicare fraud is a dollar taxpayers lose – a problem that has worsened since the COVID pandemic.
“If I had to just pick one thing to focus on to make healthcare more affordable in America, I’d go to health fraud and all the waste and abuse that accompanies it,” said Oz, who is the administrator of the Centers for Medicare & Medicaid Services. “And just to put this in perspective, we think it’s about $100 billion a year.”
BIG MEDICARE CHANGE SLASHES WEIGHT-LOSS DRUG COSTS FOR ELIGIBLE SENIORS
Medicare fraud can include billing for services that were never provided, overcharging for medical equipment, using stolen patient or doctor information, or performing unnecessary procedures, according to the U.S. Government Accountability Office.
CMS administrator Dr. Mehmet Oz is pictured on stage at the Great American State Fair in Washington, D.C., on July 6, 2026. (Angelica Stabile/Fox News Digital)
As the Trump administration ramped up efforts to combat fraud, CMS reported $41.9 billion in Medicare program integrity savings in 2025, up 59% from $26.3 billion in 2024.
CLICK HERE FOR MORE HEALTH STORIES
Medicare fraud not only harms the federal budget and steals from taxpayers, but exposes seniors to identity theft, unnecessary care, higher premiums and reduced access, Oz cautioned.
CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER
Removing corruption from the healthcare system will have the greatest impact among seniors, since “so much of the fraud is perpetrated against them,” the administrator said.
“I’m talking about people tricking seniors to give up their Medicare beneficiary numbers, which is like a credit card basically,” he said. “These scammers can take those numbers and use them for all kinds of illegitimate purposes.”
“If I had to just pick one thing to focus on to make healthcare more affordable in America, I’d go to health fraud and all the waste and abuse that accompanies it,” said Oz. (Fox News Digital)
“People are stealing from you by pretending to send you drugs you don’t want, wheelchairs you don’t need, [and] services you never asked for or don’t benefit from,” Oz added.
To prevent this, he shared his top advice for seniors: Do not give your Medicare beneficiary number to anybody, do not answer questions on a phone call from an unknown person and do not give away personal information.
TEST YOURSELF WITH OUR LATEST LIFESTYLE QUIZ
“These scammers are calling seniors, tricking them, and once they have key information, they can steal it,” he said. “And I won’t know it and you won’t know it.”
“We want to protect people who need these programs the most,” Oz went on. “You do that by making sure scoundrels don’t corrupt the systems and steal money out of the till that is designed to help folks in dire straits when they’re vulnerable and in need of services.”
Seniors should never share their Medicare information with unknown people, the administrator advised. (iStock)
Removing fraud could “double the life expectancy of the trust fund that makes all this possible,” Oz predicted.
“If you’re worried about Medicare being there when you’re ready to retire in a couple decades, depending on how old you are, and you’re concerned that it might not last because of all the fraud that’s hitting it … you’ve got a good [reason to] worry,” he said.
CLICK HERE TO DOWNLOAD THE FOX NEWS APP
“If we take the fraud out, we could double the life expectancy, which means you, your kids, your kids’ kids … they could all benefit from this beautiful safety net program.”
-
New Hampshire2 minutes agoNew hampshire set to approve world’s first $100 million bitcoin-backed municipal bond
-
New Jersey5 minutes agoPolice conclude investigation at Walmart in Cherry Hill, officials say
-
New Mexico10 minutes agoMonsoon high shifts slightly west but rain is still possible Wednesday in New Mexico
-
North Carolina17 minutes agoNorth Carolina Republican operative shaping the state’s early voting plans is reassigned
-
North Dakota20 minutes agoWest Fargo Attorney Chosen for North Dakota Ethics Commission Position
-
Ohio25 minutes agoJeff’s Donuts opens first Ohio location, open 24 hours
-
Oklahoma32 minutes ago5 Things To Know: Oklahoma County inmate death, deadly OKC hit-and-run
-
Oregon35 minutes agoOregon to ask court to delay Paramount deal for 60 days while it reviews records
