Volkswacht Bodensee - French teaching unions call strike over 'unacceptable' heat

With most of France under red alert, the heatwave is expected to reach its peak on Thursday.

"The health of staff and pupils, as well as their working conditions, are being put at risk," the unions said in a joint statement.

They denounced a "clear lack of preparation" for heatwaves.

"For the past 48 hours, we have received increasing alerts from our colleagues about the conditions in which they work," the unions said.

They cited "fainting incidents," an increase in visits to the school infirmary and trips to emergency services and a "surge in workplace health and safety reports".

"In light of the worsening situation and the government's inaction," the unions said they had filed strike notices.

They also encouraged staff to make use of existing measures, such as exercising their right to withdraw from work in cases of serious and imminent danger.

Most French schools are not equipped with air conditioning, and around 3,500 schools were closed on Thursday.

Thousands more schools were forced to adjust their schedules, and many that remained open struggled to teach pupils in sweltering classrooms.

A sign pinned to the door of a school in eastern Paris on Thursday read: "Temperatures in classrooms reached between 32C and 34C by 8 am."

A.Ruegg--VB