More than 10,000 excess deaths were reported across European countries during the record-breaking heat wave that swept western Europe in late June, official data showed.

The vast majority – more than 9,000 – were among people aged 65 and above, according ⁠to data published by EuroMOMO, ⁠a network backed by the European Centre for Disease Prevention and Control and the WHO.

Extreme heat can kill by causing ​heat stroke or aggravating cardiovascular and respiratory diseases, with ​older ⁠people among the most vulnerable.

"To have this kind of excess at this time of year is unusual. It’s really high," Lasse Vestergaard, Chief Physician at Denmark's Statens Serum Institut, which hosts EuroMOMO, told Reuters.

"It is difficult to explain this high excess mortality by anything but the extreme heat," Vestergaard added.