The huge flying foxes were killed as temperatures hit record highs of 44.1C in Casino, around 600km north of Sydney, in New South Wales.

A massive clear-up is under way to remove the decomposing remains, and volunteers from wildlife charity WIRES are working to save hundreds of baby bats found clinging to their dead mothers. But local residents have been urged not to touch bodies or launch their own rescue efforts for fear they could be infected with diseases such as the lyssavirus, which is closely related to rabies.

“Some areas along the riverbank are inaccessible and the stench from the rotting carcasses will be quite unbearable for some time yet,” local council manager John Walker told the Australia Telegraph.

“People should avoid the area and not try to help living bats themselves as they could bite and scratch and some carry the lyssavirus.”

Photographer Dee Hartin told Huffington post UK of the horrific scenes. “What I saw when I got there was beyond belief. There were hundreds of them all over the ground everywhere I looked,” she said.

“They were not only on the ground dead but hanging in the trees as well. I saw many young ones around three-four months old clinging to their dead mothers or hanging in the trees next to them. It was a horrific sight and I was distressed to see such a massive loss of life.”

This is not the first time Australia’s hot weather has killed huge numbers of bats – up to 100,000 fell from the sky in Queensland in January.

Bat Conservation and Rescue Society president Katrina Faulkes-Leng told the Courier Mail the creatures could not tolerate extreme heat. “Once it hits a certain temperature inside the colony bats start to suffer heat stress,” she said. “If we can get into colonies then, and spray with water, we can stop the stress becoming heat stroke, which kills them.”