World climate temperature map. Detailed vector illustration

Climate Change is Bad For Our Health

When it comes to natural disasters and health, heat is public enemy No. 1. As global temperatures rise in response to human activity, doctors and scientists expect heat to make more and more people sick.  

Heat at night disrupts sleep while the body attempts to cool down, increasing risk of cardiovascular disease, chronic illnesses, inflammation, and mental health issues. Higher temperatures increase pollution, another significant cause of sickness and death. And climate-induced mental health issues are so prevalent the American Psychological Association created a climate-change guide to help mental health care providers treat climate anxiety and grief (AKA solastalgia). 

“If we accept that climate change means hotter temperatures, more extreme temperatures, more extreme weather events, and more drought and wildfire, then we must also consider the downstream health effects, especially on vulnerable individuals who are disproportionately affected,” says Christopher Tedeschi, MD, director of emergency preparedness for the Department of Emergency Medicine at Columbia University's Vagelos College of Physicians and Surgeons.  

The World Health Organization says climate change is the single biggest health threat humans face at this time. Tedeschi agrees. We asked him if health care workers are prepared, and what everyone can do to preserve their health in the face of climate change. 

Climate change is a health crisis 

The impact of climate change on health is a smoldering crisis, a crisis Tedeschi fears will snowball over the next several years and negatively impact everyone’s health in ways that we may not yet understand. 

The correlation between climate change and health 

The changing climate directly affects our health. It’s clear deaths due to heat illness during or immediately following a heat wave are related to climate change. And we know that heat waves have become both more frequent and more intense. But sometimes the relationship between climate and health is more subtle. As temperatures increase, the impact of such chronic diseases as heart disease, diabetes, respiratory illness, and mental health will be amplified and cause more deaths. 

Once we collectively understand that climate change is partially responsible for the increased frequency and severity of wildfires in California, for example, it’s easy to see the relationship to health effects: smoke inhalation, asthma exacerbations, and even disruptions in primary care due to displacement of patients and medical staff and facilities.  

And you don’t need to go across the country to experience how climate change is bad for health. At CUIMC during a recent heat wave, Tedeschi took care of an elderly patient with COPD. The patient arrived in an ambulance short of breath, despite the oxygen used nearly 24/7. He had been outside in the hot weather all day, with worsening breathing, when he discovered the elevator in his building was out of service. He was so depleted of energy and short of breath due to the heat, he could not climb the stairs and ended up in the emergency room. 

The medical term for climate-related illnesses 

The medical community has not settled on a good description for health outcomes associated with climate change. Tedeschi likes the term "climate exacerbated illness" and notes it's used more regularly in hospitals and in the news. 

Some doctors and hospitals have started using the category “climate change” as a cause of patient problems. As more do the same we will have a real record of the effects and hard numbers to show the increase in patients with climate-related conditions, not only anecdotes.  

What doctors and hospitals are seeing 

This summer alone New York City has recorded an increase in patients in the emergency room directly affected by heat. Some have heat stroke, heat exhaustion, or dehydration. A greater number come to the hospital with exacerbations of respiratory diseases, like COPD and asthma, and congestive heart failure. The mental health burden is noticeably increasing too. The volume of patients with issues that can be clearly linked to the heat has been greater than in past summers.  

Greatest concerns about climate change and health 

The big events come to mind first: health effects of extreme weather events, sudden heat waves, fires, and flooding. Sudden events create spikes in morbidity and mortality, where we have to do a better job of mitigating risk.  

But the real dangers may be more insidious. For instance: increased risk of vector-borne diseases as our environment warms, whether it be from ticks, mosquitos, or other vectors. The Miami Dade Department of Health reported a third case of locally transmitted Dengue fever. We’ll see more reports like that as things heat up and the range of disease-causing mosquitos increases.  

What we should all be concerned about  

The immediate problem and the big picture of climate change should concern everyone. Everyone’s health can be affected by climate change in profound ways. Big climate related events—hurricanes and floods, for instance—disrupt our already strained health care system and interrupt care for people with chronic disease. Extreme heat will exacerbate disease and damage mental health because we will all worry more.  

We should be concerned about people exposed to heat and smoke and fire because of their jobs or where they live. We do not know how we’ll be able to provide appropriate care for them when they develop asthma, emphysema, dehydration, or cardiac problems.  

What to do if you think climate change is impacting your health   

Talk to your doctor about your health risks, how they might be affected by climate, and what you can do to reduce them. It may lead to different medications, changes in activity, a plan for what to do if the power goes out during a storm, or even a strategy for reducing the anxiety and worry associated with something that often seems totally out of our control.  


Christopher Tedeschi, MD, is associate professor of emergency medicine at Columbia University Vagelos College of Physicians and Surgeons and director of emergency preparedness for the Department of Emergency Medicine at Columbia University Irving Medical Center.

Extreme Heat is Bad for Your Health | Columbia University Irving Medical Center