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Excessive Heat Warning: The Health Science of Extreme Heat Waves

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Excessive Heat Warning: The Health Science of Extreme Heat Waves

EExtreme heat is on the way in many parts of the United States this week. The Midwest and Northeast in particular will experience weather conditions that will cause them problems The National Weather Service’s highest heat risk category – when lack of cooling or hydration can put almost anyone at risk.

It’s a new labeling system for the NWS, which launched the experimental assessment at the Centers for Disease Control and Prevention in late April in response to the growing danger of extreme heat. Last year was the hottest year in 2000 years here in the Northern Hemisphere.

“Many people don’t realize how deadly extreme heat can be,” Jennifer Wang, executive director of the Yale Center on Climate Change and Health, said in an interview with STAT last month. The heat risk index aims to emphasize that connection, base his thresholds on a combination of local temperature and mortality data.

It’s just the first heat wave of the summer, and more are likely to follow. If you need proof to convince stubborn family members that they are not immune to extreme heat and that we should turn the air conditioner in the window, STAT has your back.

How do we measure extreme heat?

Some experts say the U.S. is lagging behind other countries when it comes to both recognizing the risk of extreme heat and providing resources to address it.

The heat index – or ‘feels like’ temperature, which takes into account humidity – is often used to measure heat stress on the body. But some experts argue that we should move away from the heat index as a way to measure risk, and instead use wet-bulb temperature, which rates risk based on wind speed and solar radiation, in addition to temperature and humidity. The temperature of the wet bulb bulb is measured by placing a thermometer in the sun, covered with a wet cloth. This is different from the heat index method, which uses a thermometer in the shade.

Some experts also believe that in addition to new measurements, we need a new system to warn people about extreme heat. Heat alerts are issued based on the likelihood of high heat, but people may experience poor health outcomes at a lower temperature than an alert is triggered for. These systems often simply look at the peak temperature on a given day, but health impacts are also linked to high nighttime temperatures, especially for vulnerable populations – a factor that the new NWS tool takes into account.

What can the heat do to you?

It starts at birth. Many studies have shown that heat waves are linked to an increased risk of preterm birth. A recent paper analyzed more than half of all births in the US between 1993 and 2017, finding that in the days following a heat wave, preterm births increased by 2%, and premature births increased by 1%.

Perhaps the biggest health risks during heat waves are to our cardiovascular health. When the body suffers from extreme heat, the heart begins to pump faster to distribute boiling blood to extremities such as fingers and toes, and away from sensitive organs. Heat stroke occurs when the body fails to cool itself, and there is also a risk of heart attacks, strokes or heart failure at high temperatures.

A study last year found that extreme heat was linked to more than 1,600 cases of these types of cardiovascular deaths per year in the US between 2008 and 2019. And the authors predicted that these deaths could increase by as much as 233% annually if temperatures continue to rise. as a result of climate change.

Heat can also put your heart in ‘oxygen debt’, according to a study published earlier this month. About 60 study participants wore NASA-designed wetsuits that increased their internal temperatures. A third of the oldest, least healthy participants had blockages in their blood flow. But even the younger and healthier participants showed responses to the heat at surprisingly mild temperatures, researchers said, which has serious consequences for long-term heat exposure in the real world.

And if all this is stressing you out, some experts think there’s probably also a link between rising temperatures and mental health.

“The rates of suicide, depression, anxiety and substance abuse are skyrocketing. And that’s not just because of climate change, but we know that every time this population is questioned about climate change, it’s clearly a source of serious problems,” said John Balbus, director of the ministry’s Climate Change and Health Equity Office of Public Health. Human Services, said in an interview with STAT last year. “People decide not to have children, people worry about their future.”

What can be done?

Maybe one day we will all get prescriptions for AC, but today is not that day. Currently, not enough people have access to air conditioning, and this is just one of the factors experts are considering as they look to a future of even more extreme heat.

There is no federal heat standard to protect outdoor workers from extreme heat, leaving states and local governments to devise their own approaches to this pressing public health problem. Last year, the Miami-Dade Board of County Commissioners voted on such a proposed standard. It would have been the nation’s first comprehensive local heat standard for outdoor workers, going beyond requiring rest breaks and giving local officials regulatory teeth in an area where real oversight is lacking.

But it fell through, and months later the state passed a law banning local municipalities from enacting such standards. This kind of preemption also exists in Texas, where more than 300 people died from the heat last year.

In addition to necessary policy changes, experts are also calling for greater recognition of climate change and extreme heat within the medical sector, including more education for doctors on how to best help their patients stay safe in extreme heat. Last year, a survey of more than 450 clinic workers in the US found that 77% did not have the knowledge or tools to implement climate change preparedness at work, but more than 80% were interested in education and training on how on which patients can be protected. This also included the HeatRisk launch at the end of April new guidelines from CDC for healthcare providers to manage the impact of heat on patient health.

The latest standard of care for extreme heat in hospitals is kind of creepy: immersive cooling in a body bag filled with ice and zipped shut to about shoulder height. These bags can cool a person twice as fast as traditional methods and take up little space.

There are a few practical options at home. If you have access to an AC, that’s great, but many people don’t. Electric fans are a good option. If you’ve heard that they might not be safe, fear not. A 2019 study found that recommendations against these devices were not based on scientific evidence.

“The idea that we should recommend, ‘Oh, well, you should buy an air conditioner,’ that’s a bit of a privileged recommendation,” Ollie Jay, associate professor of thermoregulatory physiology at the University of Sydney in Australia, said that year in an interview with STAT about the research. “We should think about more environmentally responsible solutions for people who find themselves in a situation where they cannot afford these types of interventions.”