As heat and humidity rise outdoors, what’s happening within the human body can become a life-or-death battle over a few degrees.
According to researchers who place people in hot enclosures to study what happens to them, the key danger point outside for disease and death from unrelenting heat is several degrees lower than previously assumed.
With most of the United States, Mexico, India, and the Middle East experiencing blazing heat waves exacerbated by human-caused climate change, numerous doctors, physiologists, and other specialists told The Associated Press what happens to the human body under such conditions.
The body’s resting core temperature is usually around 98.6 degrees Fahrenheit (37 degrees Celsius).That is only 7 degrees (4 Celsius) away from heatstroke, according to Ollie Jay, a professor of heat and health at Australia’s University of Sydney, where he directs the thermoergonomics laboratory.
Dr. Neil Gandhi, emergency medicine director at Houston Methodist Hospital, stated that during heat waves, everyone who arrives with a temperature of 102 degrees or higher and no evident source of illness will be evaluated for heat exhaustion or more severe heatstroke.
However, the greater killer in heat is the strain on the heart, particularly for persons with cardiovascular problems, Jay said.
Again, blood rushes to the skin to help the body shed core heat. This causes blood pressure to decline. The heart responds by attempting to pump extra blood to keep you from fainting.
“You’re asking the heart to do a lot more work than it usually has to do,” Jay told me. For someone with a heart issue, “it’s like running for a bus with a dodgy hamstring.” “Something will give.”
The third major cause is severe dehydration. Jay explained that sweating causes people to lose liquids to the point where their kidneys can be significantly stressed.
According to Dr. Renee Salas, a Harvard University professor of public health and an emergency department physician at Massachusetts General Hospital, dehydration can lead to shock, which causes organs to shut down due to a lack of nutrition, resulting in seizures and death.
“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 told reporters. Jay said that dehydration lowers blood flow and exacerbates heart difficulties.
Heat affects the brain as well. It can lead to disorientation or difficulty thinking, according to some doctors.
