More than half of France's regions are under a red heat alert, as the country braces for sweltering temperatures due to an intensifying heatwave.
Highs of more than 40C (104F) are expected across parts of western France on Monday, with temperatures expected to hit 42C in Bordeaux, according to weather forecaster Météo-France.
Some 845 schools have been shut for the day, while a further 1,800 are allowing pupils to finish classes early, according to the ministry of education. But more than a million high school students are due to take their oral final exams for the baccalaureate amid the soaring heat.
The French government has warned people not to try to cool off in unsupervised areas such as lakes and rivers, after 13 drowning deaths at the weekend.
Dozens of other regions in France are under an orange alert, with an estimated 63 million people in total affected across the country.
The national railway operator SNCF urged "vulnerable" people to avoid or postpone train travel this week, while in Paris, several train lines reduced their services on Monday due to the heat.
Belgium's train operator also announced some peak hour trains would be cancelled for Monday and Tuesday. Temperatures in Belgium are expected to reach record levels in the coming week, the IRM meteorological institute said.
The rising temperatures are being driven by hot air moving north from the Sahara desert, which is in turn trapping hot air over western and central Europe with forecasters suggesting the conditions could result in one of the longest heatwaves in recent years.
Météo-France said of the 51 heatwaves recorded in France since 1947, 34 have taken place since 2000 and 26 since 2011.
Spain's state weather service Aemet warned of "extremely high" temperatures for the season until Wednesday "between five and 10 degrees above what is typical".
A red alert has been issued for the Basque country, with highs in San Sebastian forecast to rise to 40C, almost double its average for this time of year.
Madrid is forecast to hit 39C on Monday while in Italy, temperatures are predicted to reach 37C in Rome.
It comes as the UK's Met Office issued a rare red heat warning on Wednesday and Thursday for parts of England and Wales, with forecasts suggesting temperatures could reach 38C (100F) in some areas this week.
The conditions in France follow a weekend in which the mercury hit 40C, prompting an alcohol ban at the annual Fête de la Musique, a national festival that sees large crowds celebrate on the streets of most cities.
The ban applied to all events organised by the French state and its agencies, and aimed "to preserve emergency and healthcare services and allow medical staff to focus on caring for the most vulnerable", the government said.
In the south-west Gironde region, local authorities on Sunday said three people - aged between 80 and 95 years - had died, partly due to the intense heat.
Health Minister Stéphanie Rist told French public broadcaster TV1 Info on Monday that many "fellow citizens will suffer" during the hot weather, and called on people to keep a "close eye" on relatives and neighbours.
While the hottest temperatures are expected on the western coast, highs are expected to hang around 36C to 40C across much of the rest of the country, Météo-France said.
The forecaster warned that the heatwave will be "widespread, long-lasting and intense" - with temperatures not expected to drop until the end of the week.
