Fact check: Throwing cold water on heatwave disinformation as Europe swelters

Fact check: Throwing cold water on heatwave disinformation June 26, 2026With temperatures of over 40 degrees Celsius (104 degrees Fahrenheit) this week, much of Europe is in a heat-induced stupor. France received the worst of it, recording its highest-ever temperature on Tuesday, leaving thousands of homes without electricity. More than 55 people have drownedas residents have jumped in the water to try to cool down. Extreme weather typically brings a storm of disinformation with it; this heatwave is no different. The message "must connect to something people are directly affected by," Anna Siewiorek, Head of Climate Disinformation Resilience at the Climate&Strategy Foundation, told DW. "We feel the heatwaves, we feel the storms or floods — and we're emotionally affected by it because we have economic fear, we fear about our loved ones, for the infrastructure we built and so on." DW Fact check took a look at some of these false and misleading claims. Here are the cold, hard facts. Spain's fake air-conditioning ban Claim: "Spain is banning people from setting their air-con below 27C," one user wrote in a postviewed more than 800,000 times. Fact check: False That claim is a screenshot of a Time Out headlinewritten on August 3, 2022. At the time, the Spanish government temporarily set that rule in response to Russia's invasion of Ukraine and the resulting energy crisis in 2022. The Spanish government limited the heating and cooling temperature to 19 and 27C.The royal decree-law was only ever appliedto public buildings and shops. It expired a year later. Other countries took similar steps at the time: Germany mandated that lights be switched off around monuments, France institutedfines if air-conditioned shops left their doors open, and Ireland handed out grants to insulate attics and cavity walls. Is sleeping with a fan on 'extremely dangerous'? Claim: "Sleeping with a fan on is extremely dangerous and most people do it every single night," wrote another user in a postviewed 1.7 million times. The post describes how a fan launches "a silent attack on your respiratory system," by evaporating moisture from your mouth and nose, drying out your eyes, and causing a stuffy nose or a "pounding headache". Fact check: Misleading It's true that fans can dry out the eyes, nose and mouth, but the claim is wildly overstated. The World Health Organization, theCenters for Disease Control and Preventionin the US and the UK's National Health Service all recommend using an electric fan during extreme heat. Peer-reviewed research backs this up. A 2019 sleep study published in Indoor Air found elderly participants slept just as well — measured by brain activity and stress hormones — with a ceiling fan at 30C as they did in an air-conditioned room at 27C. One team of researchers found that "the protective benefit of fans appears to be underestimated by current guidelines." The guidelines warn not to use a fan if the temperature is above a certain level — some say 35C, some say 40. While the exact number is debated,researchers agree that at a certain point fans heat you up instead of cooling you down, as the air being moved is hotter than the body's skin. The NHS also includes a disclaimer that the fan shouldn't be aimed directly at your body, as this can cause dehydration. The evidence landscape around fans and sinuses is thinner. Dr. Praveen Bhatia, a respiratory doctor with a background in sleep medicine, told Tom's Guide that sleeping with the fan on "can dry out your mucus membranes, particularly in the nose and throat, which can cause nasal congestion, a sore throat, or a dry mouth by morning." "For those with pre-existing respiratory conditions or allergies, a fan can circulate dust and pollen, aggravate symptoms and actually disrupt sleep quality," he added. So, a fan is a genuinely useful intervention for heat, with some real drawbacks. But calling it "extremely dangerous" is scientifically unfounded. The link between heatwaves and climate change Claim: "Who else is tired of normal summer heat being called 'climate change' by dramatic fools?" one user wroteon X. This sentimentwas echoedacrosssocial media in numerous posts. DW Fact check: False The scientific consensus around climate change and heatwaves is well-established. Humans have caused the planet to warm by burning fossil fuels — that warming is directly linked to an increase in extreme weather, including heatwaves, droughts, and wildfires around the world. This record-breaking heatwave would have been "virtually impossible" without climate change, found a rapid studyfrom the World Weather Attribution group. "All the heatwaves today — they occur more frequently," Siewiorek said. "There is a larger area being covered with the heat, and it wouldn't have happened without anthropogenic climate change." Europe is warming twice as fastas the global average. Last year was the third warmest year on record, according to the EU's Copernicus Climate Change Service program. The firstand secondhottest years? 2024 and 2023. And the Lancet maintains a trackerof health impacts from climate change — the 2026 edition found that virtually every region in Europe saw an increase in heat deaths over the last decade compared to 1991-2000. Admittedly, there's a problem with Copernicus reports and well-established facts and figures about the Earth's warming: "Scientifically proven information is boring," Siewiorek said. "We're not that into engaging with that." But don't be fooled by claims that arouse excitement or emotions. Stay grounded in the facts — and, while you're at it, stay cool. Edited by: Sarah Steffen