Climate change was responsible for the extreme weather, Tedros said, warning that Europe was warming at "twice the global average".

"Driven by climate change and global warming, the phenomenon of the 'once-in-a-generation' heatwave is now occurring nearly annual," he said.

He called on European countries to "implement heat health action plans", as part of a push to safeguard health in the face of climate change.

The extreme weather has led European authorities to take drastic measures to prevent heat-related illnesses.

On Thursday, the Dutch music festival Defqon.1 was cancelled following an unprecedented code red warning for extreme heat.

In Paris, officials banned drinking takeaway alcohol in public and cancelled the city's pride march to help stretched emergency services.

The ban began at noon on Friday local time ahead of France's World Cup match with Norway and lasted until Sunday morning.

At least 74 people have drowned in France since the beginning of the heatwave, according to Interior Minister Laurent Nuñez.

Most of the deaths occurred in "unsupervised bodies of water such as rivers, lakes and ponds", he told Le Parisien newspaper on Saturday.

The record-breaking June heatwave has been blamed on a so-called "heat dome" effect.

This weather pattern results in air sinking down through the atmosphere, which compresses and heats up as it hits the ground.

This sinking air also dries out, meaning no clouds can form, so strong sunshine is able to heat the ground up even further.