The world is facing a climate change-fueled health crisis — from increased emergency department visits due to heatstroke, exacerbated asthma and even heart attacks to injuries and illness linked to severe storms, Axios' Tina Reed reports.

Why it matters: The growing threats to human health only promise to get more complex and expensive, and health systems have to make major changes to how they prepare for those threats, experts say.

• They're already estimated to exceed $800 billion a year in increased health costs.

"It's challenging because this is happening fast," Beth Schenk, executive director of environmental stewardship for Washington state-based Providence health system, tells Axios.

• Last summer, the health system found itself in the center of a "shocking" heat wave in the Pacific Northwest at the same time that its workforce was already stretched thin due to COVID surges.
• The extreme heat stressed its buildings' cooling systems and forced the health system to reduce services in some cases even as its emergency rooms were filling due to heat-related illnesses, she said.
• "The requirements for your hospitals are to be appropriate for your climatic conditions. Well, our climatic conditions when we built those hospitals were not for 116 degrees," she said.

Zoom in: During California's record-breaking heat event earlier this month, Kaiser Permanente switched to generators for power at its individual facilities to help reduce the stress on the state's electric grid, said Ramé Hemstreet, Kaiser Permanente's chief sustainable resources officer.

• The goal was to ensure that more individuals in the community kept their power, including their cooling units.
• "It highlights the fact we need to think about resiliency more broadly," said Hemstreet.

The big picture: The World Health Organization (WHO) calls climate change "the single biggest health threat facing humanity."

• Climate change has also been linked to increased risks for kidney disease, obesity and diabetes, injuries, the transmission of infectious diseases, some cancers and poorer mental health.

What they're saying: "[T]he combustion of fossil fuels is contributing to a massive epidemic of chronic disease around the world that dwarfs AIDS, malaria and tuberculosis combined," said Gary Cohen, president and founder of Health Care Without Harm, a group that focuses on reducing health care's carbon footprint.

There's a growing recognition among U.S. health systems that the threats from climate change will have a major impact on their operations.

• "A lot of health care systems have started to grapple with the direct physical risks to their own facilities," said Brodie Boland, a leader in McKinsey's work on climate risk in the real estate and infrastructure sectors.

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The combination of extreme heat and air pollution is extremely lethal, and this noxious mix is likely to become more common as global warming worsens, Axios' Andrew Freedman reports.

The big picture: It has long been known that particulate pollution emitted from car tailpipes, factories and power plants can aggravate chronic health problems and prove deadly. Add extreme heat, and the threat is especially dangerous.

• Particulate matter refers to tiny airborne particles that are about the width of a human hair.
• In addition to cars and factories, wildfire smoke also emits such pollution.
• This week, smoke from multiple nearby wildfires prompted the National Weather Service to warn residents of large parts of Oregon, Washington, Montana and Wyoming to "[s]tay inside if possible. Keep windows and doors closed."
• "If it's too hot, run air conditioning on recirculate or consider moving to a cooler location," the Sept. 12 warning stated.

According to a study published in June in the American Journal of Respiratory and Critical Care Medicine, co-exposure to heat extremes and particulate pollution is likely to become more frequent due to human-caused climate change.

• The study found that co-exposure to both extreme heat and air pollution at the same time "had a greater mortality effect" than if you just added their effects together, according to Mostafijur Rahman, the paper's lead author and a postdoctoral fellow at the Keck School of Medicine at the University of Southern California.

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A 2021 heat wave that killed at least 157 people in Washington state drove home why even regions accustomed to fresh air and moderate temperatures need to calibrate their public health efforts to confront extreme climate events, Axios' Arielle Dreher reports.

Why it matters: The dual threats of extreme heat and smoke from wildfires can be fatal in places where many households lack air conditioning, or they could worsen chronic heart and lung diseases.

How it works: King County, one of three counties in the Seattle area, undertook a heat mapping project to identify areas with hard landscapes and less shade that hold heat longer to help guide decisions like where to open cooling centers.

• The public health department established temperature thresholds at which point communities would open cooling centers.
• Emergency management officials plan to send push alerts to landlines and cellphones ahead of extreme weather events, urging recipients to seek out a cooling center and to check in on vulnerable neighbors or family members.
• "Maybe that will get people to start to understand that heat here in the Pacific Northwest is something they need to take seriously and is a killer," Brendan McCluskey, emergency management director at King County, tells Axios.

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Climate anxiety is an increasingly accepted phenomenon that many psychologists and therapists are tailoring their practices to treat, Andrew reports.

The big picture: The symptoms are especially prevalent among young people, and while it's not treated as an official clinical diagnosis, it can be debilitating at times, mental health professionals tell Axios.

• The experience of climate anxiety, referred to more broadly as "ecoanxiety," can be life-altering and distinct from other anxiety-provoking periods in someone's life, said psychotherapist Caroline Hickman, who is based in Bath in the U.K.

Zoom in: Hickman was the lead author of a broad study on climate anxiety and its effects on young people around the world that was published in The Lancet late last year.

• That study of 10,000 people between ages 16 and 25 in 10 countries found greater levels of concern and more acute distress associated with climate change than she and her colleagues expected, Hickman said.
• "This is a level of horror and dread and distress I have not encountered before," said Hickman.

Between the lines: The Lancet study found that about 60% of respondents were very or extremely worried about climate change.

• Levels of concern were high in vulnerable nations like the Philippines and developed nations alike.

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Climate change is scrambling the way we fight infectious diseases and adding a stealthy public health threat to the heat waves, droughts, wildfires and other physically observable hazards, Axios' Oriana González reports.

By the numbers: In a study of 375 infectious diseases, 58% have at some point been aggravated by climatic hazards, researchers wrote last month in the scientific journal Nature Climate Change.

• The threat isn't confined to microbes but includes allergens that can trigger asthma, skin and respiratory illness.

Driving the news: Extreme weather events and changes in land cover disrupt habitats and redistribute mosquitoes, ticks, fleas, mammals and birds that have been connected to outbreaks of conditions like dengue, chikungunya, Lyme disease and West Nile virus.

• "We need to stop thinking about it as something that affects forests and resources and understand that it affects our health," said Erik Franklin, co-author of the Nature study and an associate research professor at the University of Hawaii.

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Health systems are increasingly responding to the threat of climate change with commitments to cut back their own carbon footprint, Tina reports.

Why it matters: Health care is a massive global industry, and shrinking its footprint could go a long way toward reducing carbon emissions.

• Health care is responsible for about 4.6% of global carbon emissions, and in the U.S., the industry is responsible for 8.5% of greenhouse gas emissions.
• "To put that in perspective, if health care was a country, it would be the fifth-largest emitter in the world," Gary Cohen, president and founder of Health Care Without Harm, a group that focuses on reducing health care's carbon footprint, tells Axios.

Between the lines: The climate impact includes the direct emissions the health systems produce from the energy they use to power their buildings, plus the emissions from all the technology within them and the transportation of their hospital fleets and their massive workforces, Cohen said.

• It also includes the anesthetic gases used in operating rooms that are ultimately vented into the atmosphere, the products they source in their complex supply chains, and even the companies supported with their investment portfolios.

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