Burns from contact with hot pavement can be difficult to treat and can take a long time to heal.

Dr. Joanne Leovy, a family physician who has practiced in Las Vegas, Nevada, for nearly 22 years, recently talked through a case with a physician-in-training who was treating one such burn injury this summer. An unhoused man — released from the emergency department after receiving treatment for a psychiatric condition — was brought back to the emergency room less than two hours later with severe burns on his feet after contact with a scorching hot sidewalk.

Asphalt burns are dangerous because they are more likely to burn deeply into the skin and soft tissue underneath than burns from other sources, like hot stoves.

They are also more likely to occur at joints — like the knees — where it’s harder for the wound to heal, so they often require a longer hospital stay.

Such injuries are just one of the hazards that are growing more common as the climate changes and intense heat, floods, and wildfires take a toll on people’s health — and on the doctors struggling to provide them with care.

“I think this is really difficult. This is really difficult for clinicians,” Leovy says.

In the United States, 73% of residents — roughly 244 million people — experienced at least one extreme heat day in 2023, increasing the danger of heat-related illnesses. And over 120 million residents breathed in poor-quality air as Canada endured its worst wildfire season on record.

As a result, many doctors are working overtime to understand the evolving threats of climate change and protect the mental and physical health of the people they care for. Many health professionals are expanding what they talk about in the office, helping patients understand their health risks and create plans to protect themselves.

Relentless heat

In Las Vegas, Dr. Leovy makes sure to talk to her patients about heat. “It’s definitely changed. This is one of the fastest-warming parts of the country,” Leovy says.

Extreme heat can harm health in many ways, and it’s especially dangerous for those with underlying health problems. It can strain the heart, increasing the risk of hospitalization, and lead to dehydration, which can cause kidney injury and blood pressure problems.

Heat can also harm mental health, with some studies showing an increased risk of violence and suicide during periods of extreme heat.

Health professionals are especially concerned about older adults, children under 5 years old, pregnant people, outdoor workers, and people living in poverty. But longer and more intense periods of extreme temperatures put all people at risk for heat exhaustion, regardless of how healthy they are.

Knowing these risks, Leovy has started to spend more time asking patients about their access to air conditioning. She sees many people who can’t afford to keep the AC running during the sweltering summer months.

She’s also spreading the word about other cooling strategies, like planting trees in urban areas.

In Miami, Florida, Dr. Cheryl Holder, a practicing internist and founder of Florida Clinicians for Climate Action, says that she spends more time counseling her patients about the dangers of extreme heat, especially for her most vulnerable patients. Between May and October, she asks questions like: “Are you ready for the heat?” and “What are you planning to do to stay cool?”

Wildfire smoke is also causing health problems

Toxic smoke and ash from wildfires can travel with the wind, degrading the air quality of people living hundreds of miles away.

Doctors are noticing that their work to keep asthma patients stable is getting more difficult on poor air quality days.

“I’ve talked to people that kind of had their asthma kicked up during a period of high wildfire smoke intensity and have had difficulty controlling it ever since,” Leovy says.

The health impacts of wildfire smoke are still being studied, but evidence suggests that breathing it makes it harder to keep asthma symptoms under control. The smoke can also reduce lung function, cause bronchitis, and even harm the heart, increasing the risk for emergency care for cardiac arrests, heart failure, and heart attacks.

Because climate change makes conditions ripe for more wildfires in the future, health professionals in regions prone to smoke exposure have started to share resources with patients about the best ways to protect themselves, including staying indoors if possible and using a certified portable air cleaner.

Changing infectious disease risks

When patients go into their health care provider’s office with signs of an infection – fevers, chills, fatigue, muscle aches – most doctors initially consider the “usual suspects” based on time of year, geographic location, and information about which infections are circulating in a community.

But warming temperatures and changing precipitation patterns are scrambling the usual suspects, in part because of warming temperatures, and a variety of infectious diseases are spreading to new regions. That’s making infections less straightforward for health professionals to diagnose.

For example, mosquitoes carrying diseases like dengue have spread from the tropics and expanded their territory into the U.S. Local transmission has occurred in Hawaii, Texas, Arizona, and Florida. During summer 2023, a few cases of locally transmitted malaria were seen in Maryland, Florida, and Texas for the first time in 20 years.

In North America, ticks carrying the bacteria that causes Lyme disease have spread well beyond their usual range. Health professionals in regions where these infectious diseases are not historically endemic — meaning not typically present in the area — may not immediately consider some of these conditions. This can delay diagnosis and treatment, and potentially result in life-threatening consequences.

Dr. Preeti Jaggi, a pediatrician and infectious disease specialist in Atlanta, Georgia, said that she is concerned about the spread of infectious disease to new regions and has noticed it in her own practice: “I have been surprised at the amount of Lyme disease that I have seen more recently in patients who have not traveled to endemic areas.”

Jaggi advises health professionals to stay aware of local public health advisories about infectious diseases and to counsel patients about the best ways to avoid infections.

Hurricanes and flooding

Disasters like hurricanes and floods also challenge health and health systems in a variety of ways.

These events directly affect access to care in some cases, damaging clinics and hospitals, forcing patients to evacuate, or disrupting transportation. The aftermath of hurricanes and flooding events can lead to even more health problems, from contaminating drinking water to increasing the risks of certain diarrhea-causing infections.

“We know that we see more diarrheal illness after heavy precipitation events,” Jaggi says, explaining that health professionals may need to anticipate this in their practices.

In Miami, Dr. Holder regularly counsels her patients about risks during hurricane season. “I inform my patients and they get hurricane preparedness handouts,” Holder said“I do this toward the end of the visit with new patients or in the beginning with established patients during ‘small talk’ catching up before the new chief complaint.”

Health care complications

On top of the health risks from climate conditions, climate change can make the practice of medicine more difficult by damaging prescription medications or interfering with treatments doctors use to control their patient’s preexisting health conditions.

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Periods of high temperatures can compromise the effectiveness of some medications and increase the risk of heat-related illness for those taking certain medications for common conditions like high blood pressure or depression. Albuterol, an inhaler used to manage asthma symptoms, is less effective after exposure to high temperatures, such as when a patient stores an inhaler in the car.

Extreme events like hurricanes can also destroy supply chains, limiting access to critical medical supplies. After Hurricane Maria devastated Puerto Rico and an IV saline manufacturing factory on the island, many hospitals experienced shortages of saline bags for months.

When health care infrastructure itself is damaged, this can interfere with appointments and scheduling for critical services like chemotherapy and dialysis.

In order to build resilience in the face of these challenges, some health care providers are proactively expanding telehealth infrastructure, building on lessons learned during the height of the COVID-19 pandemic. Leovy points out that this type of appointment is helpful at times when people are unable to access care because of weather disasters.

But Leovy worries that some patients do not understand the dangers of the intensification of weather patterns where they live, especially those who might think they are already used to high temperatures or have weathered hurricanes in the past.

“[In Las Vegas,] people are used to heat and that’s kind of a funny thing too, because people who’ve lived here a long time will say, ‘Oh, I’m used to the heat, you know,’” Leovy said. “I’ve treated older guys that were up on a roof or outdoors doing some work. ‘Oh yeah, I’ve lived here 30 years,’ when they come in with vertigo or whatever. It’s like, well, it doesn’t matter how acclimated you are, you cannot acclimate to this.”

Tom Toro is a cartoonist and writer who has published over 200 cartoons in The New Yorker since 2010.

Neha Pathak, MD, FACP, DipABLM is dual board-certified in internal medicine and lifestyle medicine. She is on the medical team responsible for ensuring the accuracy of health information on WebMD and reports...