More than two dozen countries across Europe are under extreme heat alerts today, after a high-pressure “heat dome” settled over the continent, shattering hundreds of temperature records. On Tuesday, France recorded its hottest day ever, with the temperature reaching 111 degrees Fahrenheit in southwest France. At least 40 people have drowned across France while seeking relief from the heat, a number of them teenagers. In the U.K., United Nations Secretary-General António Guterres delivered remarks to the London Climate Action Week on Tuesday as temperatures outside topped 100 degrees Fahrenheit.

Secretary-General António Guterres: “Around the world, climate disasters are becoming more frequent, more destructive and more costly. And the World Meteorological Organization has warned we ain’t seen nothing yet. El Niño is not just knocking on the door. It risks blowing the house down, turning up the heat, disrupting food and water systems, and hitting the vulnerable the hardest.”

Meanwhile, a new study published in the journal Nature Climate Change finds global heating has exposed an additional 1 billion people to extreme heat stress each year, compared to the 1970s.