It came after France recorded its all-time highest temperature of 45.9C in Villevieille on Friday. The heat was comparable to August temperatures in California’s Death Valley, according to the country's national weather service.
A 53-year-old man died while competing in a cycling race in the southwestern Ariege region, in the foothills of the Pyrenees, on Saturday.
The race was called off after several participants were taken sick due to the heat, organisers said.
Another cyclist died in the southern region of Vaucluse over the weekend, with authorities attributing the man's collapse to the heatwave.
Two people in Spain and three people in Italy also suffered heat-related deaths over the weekend.
It came as Germany, Poland and the Czech Republic recorded their highest ever temperatures for June, with meteorologists attributing the heat to a plume of hot air from the Sahara engulfing the continent.
In France, older cars were banned from the roads in four major cities to combat air pollution exacerbated by the heat, and some 4,000 schools were closed.
Earlier in the week, four people died in drowning accidents attributed to thermal shock, the French Ministry of Solidarity and Health said in a statement.
The wildfire, which was the most serious the region had seen in 20 years and destroyed at least 10,000 hectares of forest, was finally brought under control by Sunday.
But firefighters are still battling to control a fire that has already destroyed over 2,000 hectares of forest in the provinces of Castilla-La Mancha and Madrid.
Temperatures eased slightly on Sunday, but Spain’s national weather agency predicted the mercury could remain over 40C in some parts of the country.
In Italy, the Ministry of Health issued its maximum “red alert” warning for Rome, Florence, Perugia, Bolzano, Brescia and Rieti on Thursday.
A 72-year-old homeless Romanian man was found dead near Milan's central train station. Officials believe the heat may have been a factor in his death.
In Germany, temperatures of up to 39C are expected on Sunday from Saxony in the east to the upper Rhine in the west.
Over 3,000 athletes took part in an Ironman Race in Frankfurt on Saturday despite the heat.
Sarah True, one of the frontrunners of the female race, collapsed within a kilometre of the finish line of the final marathon stage of the competition.
Sebastian Kienle, who finished second in the men’s race, said: "It felt like a race against global warming - you could have fried an egg on my head."
Earlier in the week, officials imposed a 60 mph speed limit along stretches of the Saxony-Anhalt autobahn as the road surface began to deteriorate
Scientists said heatwaves in Europe are becoming more frequent, linking the intense temperatures to climate change.
Europe's five hottest summers since 1500 have all been in the 21st Century, according to climatology experts at the Potsdam Institute in Germany.
"An increase in heatwaves is one of the clearest impacts of climate change," said Hannah Cloke, a professor at the University of Reading.
"Killer heat events of this kind will become even more widespread by the middle of the century in Europe, but this outlook could get worse unless action is taken to curb future greenhouse gas emissions."
Additional reporting by Reuters