Europe's soaring temperatures are hitting the region's highest peak, Mont Blanc, heightening the risk of rockfall and new crevasses opening on its glaciers, rescuers and climbers said on Wednesday.

This has in turn meant authorities have urged climbers to delay scaling the mountain, which straddles the French-Italian border, because high temperatures have created dangerous conditions.

"The heat wave has also an impact on high mountains, it doesn't stop on the plains," said Nicolas Zickler, commanding officer of a high mountain police rescue team. "It facilitates rock falls. By fragilising the snow, it also facilitates crevasse falls."

Australian alpinist May Cooper called the conditions "terrifying."

"The routes have changed, the timing of the season has changed, the weather conditions have changed," she said.

Another Australian alpinist, Daniel Trevena, has been coming to the region for over 10 years.

"It has definitely changed in that time and routes are changing ... you can almost see it, just melting away very slowly," he said, with other high mountains in the region equally affected.

The Swiss weather service said on Monday the elevation at which water froze hit a new record high overnight, measured at 5,289 meters (17,350 ft), an altitude higher than Mont Blanc's summit of just over 4,800 meters. This exceeded last year's record of 5,184 meters.

"The decrease of the glaciers is worrying," said the president of Mont Blanc guide company Compagnie des Guides de Chamonix, Olivier Greber.

"It's not only a selfish point of view, yes we won't be able to go for a walk on glaciers, but we should not forget that glaciers are the water towers of many plains. As such, it’s important to preserve them." (Reporting by Cecile Mantovani, Denis Balibouse, Writing by Charlotte Van Campenhout; Editing by Chris Reese)