Is climate change making us sick?

Constant headaches during hot summers. Shortness of breath on smoggy days. A rising risk of tropical viruses reaching the Netherlands. The effects of climate change are no longer abstract or distant: they are showing up at the doctor. During Utrecht Science Week, a group of concerned medical students is sounding the alarm: our healthcare system is not ready. How can we prepare ourselves for the impact of climate change on our health? 

As the video shows, no one seems surprised that climate change affects our health. What’s far less discussed is just how wide-reaching its effects are. “Climate change is already in our consultation rooms,” says Isabel van der Velden, a medical student and workshop co-organiser at the Utrecht Science Week. “The question is whether doctors, and society as a whole, are well-equipped to recognise and address the symptoms.”

Extreme heat can kill

The most immediate health effect of climate change is extreme heat. “Heat stress makes people exhausted. They can’t focus, they feel tired, and in severe cases it can even be fatal,” explains Van der Velden. “Children, the elderly, and pregnant women are especially at risk.”

Extreme heat also worsens the quality of the air we breathe. In summer, smog and pollen levels rise, triggering asthma, hay fever, and COPD flare-ups. Smoke from increasingly common wildfires adds further strain. For example, in August 2025, wildfires in northern and western Spain burned through nearly 38,000 hectares in just 24 hours, almost matching the total area burned in all of 2024. This smoke makes it harder for people to breathe and harms their heart and lungs even after the fire has ended. 

Tropical diseases at our doorstep

Warmer temperatures are also changing the map of infectious diseases. The tiger mosquito, which can carry dengue and West Nile virus, has now been spotted in Italy, Spain, France, and even the Netherlands. “Dengue can feel like a bad flu,” says Van der Velden. “But if you get infected a second time, it can be very dangerous and sometimes requires hospitalisation.”

With more mosquitoes moving northward, Europe is no longer protected from tropical illnesses once confined to faraway regions. “We need to start educating people about mosquito-borne diseases,” she urges. “Simple preventive habits such as using mosquito repellent, wearing long clothing, and creating awareness campaigns should become part of our public health toolbox.”

In the eye of the storm

Climate change also threatens basic necessities such as clean water and safe food. Floods and storms can contaminate drinking water, while droughts can destroy crops, causing hunger and making people more likely to get sick.

Extreme weather events create immediate dangers as well. Strong winds and storms can cause accidents and injuries, while hurricanes, floods, and wildfires force people to leave their homes. Many end up in overcrowded refugee camps, where poor sanitation and close living conditions increase the risk of disease outbreaks. “In Vietnam, for example, a recent typhoon caused mass casualties and forced thousands of people to move, showing how severe weather can directly put human lives at risk,” she says.

When someone comes in with climate anxiety, they deserve to be taken seriously

Climate anxiety

Less visible, but no less real, are the mental health impacts. “Eco-anxiety, depression and even PTSD after disasters are gaining attention, especially among young people,” Van der Velden notes. “And yet, doctors still take mental complaints less seriously than, say, asthma or infectious diseases. But when someone comes in with climate anxiety, they deserve to be taken seriously.” 

Push for prevention

Van der Velden and her colleagues are pressing for prevention awareness. They want universities to incorporate the impact of the climate crisis on physical and mental health into medical training, so that future doctors can address these issues effectively.

But with mental healthcare systems already stretched, there’s only so much individual doctors can do. She believes communities can play an important role. “Think of peer support groups or safe spaces at universities or workplaces where people can share their worries about climate change and support each other. I think that would help a lot.”

Climate action, the second-year student stresses, can also bring health benefits or, at least, counteract the negative ones. “Positive activism, such as joining a community clean-up, and seeing others care as well can help reduce feelings of anxiety or depression.”