A severe heat wave is gripping much of Europe, driving down river levels, fuelling deadly wildfires and straining nuclear power generation across several countries. Nations including Hungary, Romania, Bulgaria, Serbia, Greece, France, Italy, the Czech Republic and the UK are all affected, with the crisis touching energy security, water supplies and public health simultaneously, and highlighting how vulnerable critical infrastructure is to extreme heat.

The Danube has fallen to historic lows, nearly forcing an overnight shutdown of Hungary's Paks Nuclear Power Plant, with Prime Minister Péter Magyar saying it came within "a few millimetres" of closing entirely; Romania carried out controlled explosions to redirect cooling water and shut two reactors. The receding waters have also exposed WWII-era German warships scuttled in 1944 along Serbian riverbanks, while a Bulgarian cruise ship ran aground, forcing the evacuation of nearly 200 tourists. In Greece, more than 500 firefighters are battling blazes near Athens, with five deaths linked to the fires since Sunday, including two helicopter crew killed in a mid-air collision; France's fires are largely under control, though unexploded WWII munitions have since been found in burnt areas. Italy has placed 25 of its 27 major cities on red heat alert, with the remaining two to follow by Thursday, the Czech Republic recorded its highest-ever overnight temperature of 27.9°C, and the UK has issued heat health alerts covering eight English regions.