From Britain and France to Germany, Italy, Austria and Serbia, Europe sizzled under a record-breaking ball of heat rolling across the region.
Scientists said the heatwave was the worst recorded for Europe, where the climate is changing faster than anywhere else.
Temperatures were probably past their peak in France and Britain, where records for June have been broken.
But in Italy, the heat was expected to intensify into the weekend, bringing the summer's first readings of 40C.
At least 55 deaths linked to the heatwave have been reported in France, where temperatures in Paris hit 40.9C on Wednesday.
Even though temperatures were expected to ease, authorities braced for more casualties.
Across the continent, cultural landmarks have been forced to close, and farming has suffered.
Paris police asked organisers of major events, including the Solidays music festival, to cancel them.
Organisers of the Pride festival said they would reschedule.
Extreme heat caused the surface of the A2 motorway in eastern Germany to buckle and rupture over several lanes on Thursday evening, damaging up to 30 vehicles, leaving two people injured and forcing the highway to be closed.
Britain's Met Office extended a red heat alert into Friday for a large area of southern England, the first time such warnings have been issued for three consecutive days.
A rare "code red" alert for extreme heat was issued for almost the whole of the Netherlands and many schools were closed as temperatures up to 40C were expected.
In Serbia, authorities issued an amber alert, with temperatures of 36C expected.
Fans flew off the shelves in Britain and Asian air-conditioning manufacturers reported a European sales boom.
The heatwave, which has pushed temperatures as much as 18C above their seasonal average, according to the Reuters Climate Monitor, is being driven by a weather pattern known as an Omega block.
This traps a bulging ball of hot air over regions for extended periods, with cooler weather on its fringes.
Scientists said the record-breaking heatwave would have been "virtually impossible" without human-caused climate change, which has made this week's stiflingly hot night-time temperatures 100 times more likely than they would have been even two decades ago.
"Over the region studied, this heatwave is the most severe ever recorded," the World Weather Attribution group of climate scientists said in their latest analysis.
French authorities announced a ban on drinking alcohol in public on Friday, when France were due to play Norway in Boston in the football World Cup.
French doctors and hospital workers reported an increase in emergency calls and treatment.
Wilfrid Samut, spokesperson for the Association of Emergency Room Doctors of France, said hospitals were ill prepared for the heatwave.
"The impact on the mental health of healthcare workers is enormous," he said.
"It's apocalyptic."
8°C