(CNN) — French firefighters are battling a huge blaze in a forest just south of Paris as a devastating heatwave extends its deadly sweep across Europe.
More than seven square miles of the Fontainebleau forest have been burned, CNN affiliate BFMTV reported on Tuesday, and fire-fighting aircraft have been scooping up water from the River Seine as part of efforts to get the fire under control.
Six people are in police custody as part of an investigation into the fires, including a young volunteer firefighter who has admitted his involvement, according to the Fontainebleau public prosecutor’s office.
The 19-year-old admitted he had “set fire to twigs using a lighter and petrol,” the public prosecutor’s office said in a statement on Tuesday. A second man, also born in 2007, said he had “accidentally started a fire by throwing away his cigarette,” the statement added.
In France, intentional arson is punishable by a €150,000 fine and up to 10 years in prison, rising to 15 years if the offense involves a forest fire that endangers people or risks causing irreversible environmental damage.
A number of other fires have also broken out in other parts of the country.
Wildfires are not unusual in Europe, but the climate crisis is driving hotter, drier weather, which is setting the stage for fiercer fire seasons. They are also happening earlier in the year and are growing in intensity.
In much of France and Spain, an exceptionally wet winter left a lot of vegetation that quickly turned to tinder as three successive heatwaves sent temperatures into the high-30s Celsius (90s Fahrenheit).
That has led to a spike in the number of larger fires, according to data from the European Forest Fire Information System.
Extreme heat can also be deadly. More than 10,000 excess deaths were recorded during late June’s heatwave in western Europe, according to data from EuroMOMO, a network of researchers backed by the European Centre for Disease Prevention and Control and the World Health Organization.
More than 9,000 of the deaths were among those aged 65 and over.
Extreme heat can lead to death by heat stroke or worsen existing cardiovascular and respiratory conditions, with older people more vulnerable.
And this trend is likely to continue in the coming years as Europe is the world’s fastest-warming continent, with temperatures increasing more than twice as fast as the global average, according to the EU’s Copernicus Climate Change Service.
Heatwave across Europe
In Spain, 10 people are still missing following a fire that killed 13 people in the south of the country last week, according to the Associated Press.
More than 460 emergency workers were deployed to battle the fire near the town of Los Gallardos on the Costa de Almería, Spanish Interior Minister Fernando Grande-Marlaska said Friday.
The current death toll makes the blaze Spain’s deadliest wildfire since 2005, when 11 firefighters were killed in the central province of Guadalajara after a fire was sparked by a barbecue, Reuters reported.
Last month, Spain set national records with temperatures on some days reaching 12.8 degrees Fahrenheit (7.1 Celsius) above average, according to the national weather service AEMET.
And in England and Wales, more than 2,700 people are believed to have died from heat-related causes during heatwaves in May and June, the UK’s national meteorological office reported on Monday.
The heat has also led to a spike in the number of drownings. In Germany, at least 99 people drowned in June, the highest monthly death toll since 2003.
Beyond the immediate threat to life, heatwaves are also having important secondary effects.
For example, higher river temperatures are affecting France’s nuclear plants, which require water as a coolant. French utility EDF said generation at the Nogent nuclear plant on the River Seine will be reduced this week, for the second time this summer. Another reactor on the Garonne river in south-western France suspended production as the water temperature hit 28 degrees Celsius (82 degrees Farenheit).
Heatwaves have also led to sharply reduced crop forecasts, especially for corn (maize). European grain trade association Coceral has reduced its forecast EU and UK corn output to 52.7 million tons, down from 57.2 million last month.
France’s corn harvest, at less than 10 million tons, is expected to be the lowest in two decades. Coceral also reduced forecasts for barley and wheat production across Europe.
And more tropical weather in southern Europe is contributing to an increase in diseases carried by mosquitos and other insects. A recent Italian study found that between 2013 and 2022, the risk of dengue fever epidemics in Europe rose by 56% compared to 1951–1960.
“Diseases like malaria and dengue, traditionally confined to tropical zones, are now emerging in temperate and urban areas,” the authors said.
The-CNN-Wire
™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.