Climate Change Will Affect Pulmonary Health Across Intensive Care

Climate change is one of the biggest health emergencies across the world, likely to lead to the deaths of thousands due to how it affects both health outcomes and accessibility to health care in the immediate and long-term aftermath of the increasing natural disasters. A panel of experts weighed in on how climate change is affecting health, with a particular focus on the effects of climate change in the US, during the CHEST 2025 Annual Meeting held in Chicago, Illinois, from October 19 to October 22.

Climate Change is a Public Health Emergency

The panel took a focus on the health effects of wildfires, increased heat, vector-borne illness, and how prepared the intensive care unit (ICU) is for these natural disasters, specifically when it comes to the potential influx of patients in the immediate aftermath.

“We know that the science is abundant and clear, and we know too that increasing frequency, scale, and intensity of extreme heat, wildfires, flooding, storms, and droughts are endlessly in our news cycle,” began Stephanie Maximous, MS, MD, an assistant professor at the University of Pittsburgh School of Medicine. “This is coupled with fragile health infrastructure and public health systems, which are going to bear a greater burden.”

With the World Health Organization estimating that 3.6 billion people live in areas susceptible to climate impacts¹ and up to 250,000 estimated additional deaths, predominantly in areas of historic inequities, Maximous encouraged those in attendance to think about what they could do as practitioners to help mitigate some of these effects.

“Those with overlapping vulnerabilities are even more affected. So when we have populations who have multiple vulnerabilities, they are in even more challenging of a position, such as low-income communities, communities of color, indigenous peoples, children, the elderly and disabled, and undocumented residents. It’s really important for us to prioritize caring for our most vulnerable patients and community members,” she said.

Natural Disasters Have Unique Challenges in Health Care

Longer-term consequences of natural disasters could be felt for generations, which makes being aware of these natural disasters so important. Nicholas Nassikas, MD, assistant professor of medicine at Harvard University, highlighted the effects of wildfires, particularly on the pulmonary system.

“In almost every single study looking at wildfire smoke and asthma, there’s an association between wildfire smoke and asthma exacerbation; that literature is very clear,” explained Nassikas. “There’s also evidence that wildfire smoke is associated with [chronic obstructive pulmonary disease] exacerbation, reduced lung function, respiratory symptoms…[emergency department] visits, and hospitalizations.”

Respiratory infections could be associated with wildfire smoke, which can affect the number of patients visiting hospitals and the ICU if they have a preexisting comorbidity. Mortality also increases with an increase in particulate matter 2.5, which could also have an effect on the economy, according to Nassikas.² With particulate matter also seeping into buildings through ventilation systems and general activity through buildings, these effects may not be isolated to outside exposure. Gaps in knowledge, like what happens when people are exposed to both particulate matter and heat, need to be looked into to get a full picture of how it affects pulmonary health.

Heat is also a particular area of concern, as extreme heat can lead to sweating, decreased appetite, decreased metabolic rate, and decreased activity, which not all people are able to compensate for within their body, such as older adults or younger children, those with preexisting conditions, and those spending a long portion of their days outside.

“We may start to see more patients admitted to our ICUs after they’ve been found down or outside… If you have patients who are in a coma, have anuria, develop [disseminated intravascular coagulation], or have any cardiovascular dysfunction as a result of their heat exposure, they’re at much, much, much higher risk for mortality because of that heat exposure,” explained Rachel Wojcik, MD, a critical care pulmonologist at the University of Pittsburgh Medical Center.

Hari Shankar, MD, a pulmonologist at Penn Medicine, also pointed out that, although there are obvious immediate health effects that occur after a natural disaster, long-term damage to infrastructure could leave many without care, as happened in New Orleans after Hurricane Katrina. “People that I know [in New Orleans] talk about Charity Hospital, which was sort of a bedrock of the sort of public health infrastructure there, which still, to this day, stands empty and derelict because it sustained catastrophic damage and the authorities there have not been able to come up with a mechanism to revitalize that hospital,” he explained.

Physicians Can Play a Part in Mitigating Effects

Although these are overwhelming issues in health care, particularly in pulmonary care, there are means of trying to address them. The panelists encouraged all physicians to prioritize their vulnerable patients and communities, including advocating for the building of cooling centers, planning for emergency situations, and making sure health care is accessible in an emergency. Addressing root causes, like making sure patients have access to health care resources and trustworthy information, is also vital moving forward.

“As we’ve seen so many rollbacks in environmental protections over the last several months, using our role as pulmonologists and intensivists who take care of patients who have these lived experiences with their diseases definitely getting worse due to climate change, we can very easily offer public comment and testimony…” encouraged Maximous.

References

1. Climate change. World Health Organization. October 12, 2023. Accessed October 19, 2025. https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health

2. Law BE, Abatzoglou JT, Schwalm CR, Byrne D, Fann N, Nassikas NJ. Anthropogenic climate change contributes to wildfire particulate matter and related mortality in the United States. Commun Earth Environ. 2025;6(1):336. doi:10.1038/s43247-025-02314-0