How Does Heat Kill? It Confuses Your Brain. It Shuts Down Your Organs. It Overworks Your Heart.

 Children enjoy the cold water of a fountain at Columbus Square in Vienna as Austria is being hit by extreme heat on June 21, 2024. (AFP)
Children enjoy the cold water of a fountain at Columbus Square in Vienna as Austria is being hit by extreme heat on June 21, 2024. (AFP)
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How Does Heat Kill? It Confuses Your Brain. It Shuts Down Your Organs. It Overworks Your Heart.

 Children enjoy the cold water of a fountain at Columbus Square in Vienna as Austria is being hit by extreme heat on June 21, 2024. (AFP)
Children enjoy the cold water of a fountain at Columbus Square in Vienna as Austria is being hit by extreme heat on June 21, 2024. (AFP)

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 human-caused climate change, several doctors, physiologists and other experts explained to The Associated Press what happens to the human body in such heat.

Key body temperature The body's resting core temperature is typically about 98.6 degrees Fahrenheit (37 degrees Celsius).

That's only 7 degrees (4 Celsius) 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.

"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."

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.

Attacking the 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.

Humidity matters 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 (35 Celsius) 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 (30.5 Celsius). 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 (28 degrees Celsius), 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 (52 degrees Celsius), while the elderly had to stop at 109.4 (43 degrees Celsius). With high or moderate temperatures, the people could not function at nearly as high a temperature, he said.

"Humidity impacts the ability of sweat to evaporate," Jay said.

Rushing to make patients cool 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."



iRead Marathon Records over 6.5 Million Pages Read

Participants agreed that the number of pages read was not merely a numerical milestone - SPA
Participants agreed that the number of pages read was not merely a numerical milestone - SPA
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iRead Marathon Records over 6.5 Million Pages Read

Participants agreed that the number of pages read was not merely a numerical milestone - SPA
Participants agreed that the number of pages read was not merely a numerical milestone - SPA

The fifth edition of the iRead Marathon achieved a remarkable milestone, surpassing 6.5 million pages read over three consecutive days, in a cultural setting that reaffirmed reading as a collective practice with impact beyond the moment.

Hosted at the Library of the King Abdulaziz Center for World Culture (Ithra) and held in parallel with 52 libraries across 13 Arab countries, including digital libraries participating for the first time, the marathon reflected the transformation of libraries into open, inclusive spaces that transcend physical boundaries and accommodate diverse readers and formats.

Participants agreed that the number of pages read was not merely a numerical milestone, but a reflection of growing engagement and a deepening belief in reading as a daily, shared activity accessible to all, free from elitism or narrow specialization.

Pages were read in multiple languages and formats, united by a common conviction that reading remains a powerful way to build genuine connections and foster knowledge-based bonds across geographically distant yet intellectually aligned communities, SPA reported.

The marathon also underscored its humanitarian and environmental dimension, as every 100 pages read is linked to the planting of one tree, translating this edition’s outcome into a pledge of more than 65,000 trees. This simple equation connects knowledge with sustainability, turning reading into a tangible, real-world contribution.

The involvement of digital libraries marked a notable development, expanding access, strengthening engagement, and reinforcing the library’s ability to adapt to technological change without compromising its cultural role. Integrating print and digital reading added a contemporary dimension to the marathon while preserving its core spirit of gathering around the book.

With the conclusion of the iRead Marathon, the experience proved to be more than a temporary event, becoming a cultural moment that raised fundamental questions about reading’s role in shaping awareness and the capacity of cultural initiatives to create lasting impact. Three days confirmed that reading, when practiced collectively, can serve as a meeting point and the start of a longer cultural journey.


Imam Turki bin Abdullah Royal Reserve Launches Fifth Beekeeping Season

Jazan’s Annual Honey Festival - File Photo/SPA
Jazan’s Annual Honey Festival - File Photo/SPA
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Imam Turki bin Abdullah Royal Reserve Launches Fifth Beekeeping Season

Jazan’s Annual Honey Festival - File Photo/SPA
Jazan’s Annual Honey Festival - File Photo/SPA

The Imam Turki bin Abdullah Royal Nature Reserve Development Authority launched the fifth annual beekeeping season for 2026 as part of its programs to empower the local community and regulate beekeeping activities within the reserve.

The launch aligns with the authority's objectives of biodiversity conservation, the promotion of sustainable environmental practices, and the generation of economic returns for beekeepers, SPA reported.

The authority explained that this year’s beekeeping season comprises three main periods associated with spring flowers, acacia, and Sidr, with the start date of each period serving as the official deadline for submitting participation applications.

The authority encouraged all interested beekeepers to review the season details and attend the scheduled virtual meetings to ensure organized participation in accordance with the approved regulations and the specified dates for each season.


Hail Municipality Named Arab Green City For 2024-2025

The achievement establishes Hail as a leading Arab model for sustainable urban development - SPA
The achievement establishes Hail as a leading Arab model for sustainable urban development - SPA
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Hail Municipality Named Arab Green City For 2024-2025

The achievement establishes Hail as a leading Arab model for sustainable urban development - SPA
The achievement establishes Hail as a leading Arab model for sustainable urban development - SPA

The Hail Region Municipality has secured first place in the Arab Green City award for 2024-2025 at the 15th session of the Arab Towns Organization.

This recognition honors the municipality’s commitment to environmental sustainability, the expansion of green spaces, and the implementation of urban practices that elevate the quality of life, SPA reported.

The award follows a series of strategic environmental initiatives, including large-scale afforestation, the modernization of public parks, and the adoption of eco-friendly solutions to enhance the urban landscape and resource efficiency.

By aligning its projects with the sustainability goals of Saudi Vision 2030, the municipality continues to foster a healthy and safe environment for residents and visitors.

This achievement establishes Hail as a leading Arab model for sustainable urban development.