This summer is off to a very hot—and deadly—first.
In June and early July, intense heat waves blanketed Europe and the United States, exposing millions of people to dangerously high temperatures and humidity. The French government recorded more than 2,000 deaths in the hottest week at the end of June – which may still be an underestimate, according to officials.
The entire continent is still counting the excess deaths that occur during heat waves. Meanwhile, in the US, the hot Fourth of July holiday sent many to emergency rooms across the country, with New Jersey alone accounting for 29 deaths last week.
Health facilities are busy to meet the influx of patients on both continents as medical experts urge people to be aware of the early signs of heat stress and how to combat it. Commenting on Europe’s heat wave at the end of June, the World Health Organization warned that it was only “an adaptation” to the hot summer that climate change will bring.
Adverse Health Effects of Summer Heat Waves
More than half of Americans were under a heat warning at some point last week as temperatures rose from Texas to Maine. Washington, DC, reached 102 degrees Fahrenheit with a heat index of 117 on Saturday, a new record for the area on July 4. Similar highs were seen in New York City, with little relief at night as sweaty crowds gathered to watch fireworks displays. A less fun fact: When Thomas Jefferson took the temperature on July 4, 1776, it was 76 degrees—about 25 degrees colder than Philadelphia on Saturday.
These temperatures, especially when combined with high humidity, can interfere with the body’s ability to cool itself. My colleague Keerti Gopal reported in 2025 on the all-encompassing effects extreme heat can have on the body—from your heart to your lungs. According to the Centers for Disease Control and Prevention, some of the first symptoms of heat illness include muscle aches, cramps and fatigue. Extreme heat is characterized by symptoms such as heavy sweating, lightheadedness, nausea or vomiting and headache.
In cases suspected to be caused by heat, medical experts urge people to immediately seek shade or air, drink water, use wet cloths on the skin and lie down with legs raised.
But high temperatures can push bodies over the edge and cause heatstroke, which often comes with mental symptoms like confusion or even fainting when the body reaches a temperature of 105 degrees or higher. These conditions can be life-threatening and require immediate medical attention, experts say.
The CDC reported “very high rates of heat-related illness” in northeastern states sometime last week. In New Jersey alone, state officials estimate that more than a dozen people have died in the heat, with temperatures ranging from the 30s to the 80s, the New York Times reported.
“This was a strange heat,” said Dalya Ewais, a spokesperson for the government’s Department of Health, told The Times. “This was not your average heat wave.”
June’s heat-related death toll was worst in Europe, where heat waves blanketed much of the continent for weeks. Although the heat killed many directly, some related deaths in France were caused by drowning as large numbers of people sought relief from the boiling temperatures of local waters.
Adapting to Such a Hot Summer
French hospitals have struggled to cope with an influx of patients suffering from heart attacks, dehydration, kidney problems and other heat-related problems, the Associated Press reported.
“We thought we were ready. Actually we weren’t,” said Cédric Lussiez, director of the Paris-Saclay hospital, told the press. “The hospital was working 24 hours a day because we had to find new solutions in a short period of time.”
Some older hospitals lacked equipment such as AC units, adequate medicine refrigerators or ice machines (although a local fast-food restaurant in Paris recently donated its ice to help cool patients at the Paris-Saclay hospital, the AP reported). The French Prime Minister Sébastien Lecornu – who recently made a vote of no confidence in the government’s response to the heat crisis – announced last week an investment of 114 million to install cooling systems and updated infrastructure of health centers. The government recently ordered 30,000 cooling machines to be used in hospitals across France as temperatures continue to rise, with another heat wave this week.
The health care issue is widespread throughout Europe and beyond. In England, MRI scanners, cooling units and IT systems crashed at the end of June as heat-related illnesses increased, the Guardian reported. The United States has also struggled in recent years to meet the increased demand for health care facilities during heat waves, and it could get worse, the study shows. The number of annual heat-related emergency department visits in the US or hospitalizations is expected to reach 237,000 by 2040, according to a study published in June.
Hospitals from the US to Europe have begun preparing for heat waves by stocking up on snow and postponing non-essential surgeries. But experts stress the best way to stay safe during a heat wave is to avoid needing the emergency room in the first place: be aware of the warning signs of heat stress before a problem develops. Grist has published a 2023 guide to staying safe as temperatures rise, and the CDC and National Weather Service have heat guidelines and trackers.
More Top Weather News
The heat wave in the eastern US is like that which makes the roads tieda trend that is becoming more common across the country as temperatures rise, NPR’s Scott Neuman reports. Usually made of asphalt or concrete, roads expand and soften when temperatures rise, which could increase wear and tear, a problem that could be faced by 2024. Government efforts across the country aim to repair roads and use durable materials, but these projects are incredibly expensive.
A new study found that people are willing to pay more for a wine that appears to be able to withstand the weatherFrida Garza reports for Grist. The wine industry has struggled with climate in recent years, losing crops to extreme weather such as bushfires and drought and struggling to grow grapes in hot weather. Strategies such as installing shade cloths, growing new grape varieties and moving to more suitable locations can help prevent this loss—and make brands more attractive to consumers if they are linked to climate change, according to a new study.
To help protect Panamanian poison dart frogs from a deadly disease, researchers and conservationists are collecting some from the wild and placing them in captivity in hopes of eventually releasing them. The problem? Frogs lose their venom, leaving them vulnerable to predators. Now, researchers are working to make these amphibians toxic againAnna Gibbs reports for National Geographic. As you will learn in the episode, this is another toxic relationship that can actually be a good thing.
About This Matter
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Kiley Price
A reporter
Kiley Price is a reporter at Inside Climate News, with particular interests in wildlife, ocean life, food systems and climate change. He writes ICN’s “Today’s Weather” newsletter, which covers the most pressing environmental issues each week.
He received his master’s degree in science journalism from New York University, and his bachelor’s degree in biology from Wake Forest University. His work has appeared in National Geographic, Time, Scientific American and more. He is a Pulitzer Reporting Fellow, where he spent a month in Thailand bridging the gap between Buddhism and the country’s environmental movement.
