When it comes to heat, the human body is significantly more resilient – it’s the moisture that makes it harder to cool. And humidity, driven by climate change, is rising.
A measure of the combination of heat and humidity is called “wet-bulb temperature”, which is determined by the complete wrap Wet lamp around thermometer bulb. Scientists are using this metric to find out which areas of the world could be most dangerous for humans.
A term that we rarely hear, wet-bulb temperature reflects not only heat, but also how much water is in the air. The higher the number Sweat evaporates and cools the body.
[Wet-bulb temperature is important, climate experts say. So what is it?]
Radley Horton, a professor at Columbia University’s Lamont-Doherty Earth Observatory, says at a certain threshold of heat and humidity, “it is no longer possible to be able to sweat fast enough to resist excess heat.”
Scientists have found that Mexico and Central America, the Persian Gulf, India, Pakistan and Southeast Asia are focusing on this margin before the end of this century.
“Humid heat risks are grossly devalued today and will increase dramatically in the future,” Horton said. “As locations around the world experience previously rare or unprecedented extreme experiences with increasing frequency, we run the risk that our previous messages about extreme heat risks – already sadly inadequate – will fall short of being marked.”
You might think that being near the beach would be a great way to catch the sea breeze and cool it down. But Horton said the extreme conditions are close to the water Things can get worse. As the temperature rises, water evaporates, adding moisture to the air.
“If you were to sit in a town on the shores of the Persian Gulf, the sea breeze could be a deadly wind,” he said.
To better understand why these places are becoming too hot and humid for human endurance, you must first understand how the body cools itself.
The weight-bulb temperature that marks the upper limit of what the human body can handle is 95 degrees Fahrenheit (35 Celsius). But any temperature above 86 degrees Fahrenheit (30 Celsius) can be dangerous and deadly. Horton and other scientists noted in a 2020 study that these temperatures are occurring with increasing frequencies in different parts of the world. To put it mildly, the highest wet-bulb temperature recorded in the Washington area, known for its dirty, unbearable summers, was 87.2 degrees (30.7 Celsius).
“Extremely humid heat has more than doubled in frequency overall since 1979,” the study authors wrote.
These conditions have reached critical levels in places such as South Asia and the Middle East, and by 2075 it could have passed more regularly, scientists say.
Horton and his colleagues observed that parts of the United Arab Emirates and Pakistan have crossed the 95 degree mark for one or two hours more than three times since 1987.
In the Mexican state of Sonora, off the coast of California, scientists are also seeing a “very significant” increase in wet-bulb and air temperatures, said Tereza Cavajos, a senior researcher in the Department of Physical Oceanography at Ensenadar. Center for Scientific Research and Higher Education.
In summer, some parts of the bay can reach temperatures of 86 to 87.8 degrees Fahrenheit (30 to 31 degrees Celsius), causing water to evaporate more quickly. The combination of warm water and the rising heat trend in Sonora is pushing wet-bulb temperatures to dangerous levels.
“Only a 1 or 2 degree Celsius increase could be the tipping point for changing the effect,” Cavajos said.
The scorching heat is making life difficult, especially for communities that lack the resources to provide relief.
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Why some will survive and some will die
Even below this threshold, hard work for the cooling body. Trying to fight the effects of heat puts pressure on your heart and kidneys. In extreme heat, human limbs begin to malfunction. If you have a pre-existing condition, chances are higher.
In heatwave, extreme conditions cause many deaths due to health problems.
“It’s very clear during heat waves, more people die of heat stroke,” said Zachary Schlader, an associate professor at Indiana University Bloomington, focusing on heat stress and the human body. But even more deaths are due to heart attack. The body responds [to heat] In this way, it can weaken the limb. “
[How to cool your home without relying on air conditioning]
There are some easy ways to take care of your body during heat waves.
Protecting oneself from such pressures is inextricably linked with socio-economic status and wealth.
“The poorest people are the most at risk, and they are already suffering,” Cavajos said.
In regions such as the Persian Gulf, extreme heat is new normal: Qatar has adapted to the blistering climate so extensively that it regulates outside air conditioning. But not everyone has access to an outside air conditioner, which includes all the amenities that are created. When the rich country began construction on the venue for the 2022 World Cup, it faced a controversy over its treatment of stadium construction workers.
In 2019, the United Nations warned that during the four warmest months of the year, workers outside Qatar were working in “significant occupational heat stress conditions.”
Qatar imposed regulations in May extending the deadline, which prohibits outside labor from 10 a.m. to 3:30 p.m. in the warmer months of the year, as well as any work if the wet-bulb temperature exceeds an estimated 89 degrees. Fahrenheit.
Survival depends solely on your position in society and what it offers: access to air conditioning, heated homes, jobs that do not require extreme physical exertion under the sun, and policies to protect you from dangerous situations.
“As human beings, we have learned to adapt,” Cavajos said. “The problem is the cost. Some will not survive. ”