Hundreds of kindergartens and primary schools throughout France will remain closed until the end of the week as temperatures top 40C in many cities.
In the Essonne department alone, just South of Paris, local authorities decided to close 56 schools, according to a list published on their website.
Multiple closures were also reported in the Paris suburbs of Val de Marne and Seine et Marne, as well as in the Eastern regions of Bas-Rhin and Isere, according to BFMTV.
Education Minister Michel Blanquer told France info public radio that it was up to local authorities to decide whether or not to close schools "on a case-by-case basis," depending on their air conditioning situation.
"There may be intermediate solutions, for example, you can have classes in the morning and not in the afternoon," the minister added.
SNUipp FSU, a teachers' union, has been critical of the Ministry's handling of the heatwave.
"The Ministry recommends to 'keep children in a cool atmosphere.' How are we supposed to do this when there are no curtains, courtyards or insulation in schools?" the union wondered in a statement.
And even when schools are closed, the Ministry doesn't offer any solution to the children and their families, the union said. "For many families, collective housing does not better protect children from heat, "SNUipp FSU said.
Parts of eastern and southern France will see the highest temperatures this week, peaking on Thursday, Meteo France said. The current record temperature for June stands at 41.5 degrees, registered near Narbonne in southern France in June, 2003.
“We could see temperatures in localized areas hit record highs,” Meteo France said. “This heatwave could be remarkable for how early it has come as well as its intensity.”
The unseasonably early heatwave has been caused by a storm stalling over the Atlantic Ocean and high pressure over central and eastern Europe, causing hot air to be sucked up from the Sahara desert, weather site AccuWeather said.