For the second time this year it is raining bats in Australia. That shouldn’t be a sentence, but with record heatwaves now a regular thing, sadly this occurrence seems to be on the rise.

Not only is it incredibly sad to see these threatened animals dropping like flies, but their deaths are creating a health hazard for humans who live nearby too.

Conservationists and wildlife volunteers estimate that around 4,000 spectacled flying foxes have perished this week alone, thanks to soaring temperatures experienced in Queensland, north Australia, reaching a high in Cairns of 42.6°C (108°F) this week.

The spectacled flying fox, or spectacled fruit bat, which is endemic to north Queensland, has already been struggling this winter thanks to the very dry season affecting its food sources, Maree Treadwell Kerr, president of the Bats and Tree Society of Cairns, told The Guardian.

The increasingly frequent and severe extreme weather conditions, like heatwaves, are putting the future of this species in real danger.

“It’s never had a heat stress event before because it’s in the tropics,” she said. “It’s an estimate, but we’ve probably lost more than 10 percent in the past week.”

“What’s scary about this one is the spectacled flying fox has been hit,” Tim Pearson, a wildlife ecologist specializing in flying foxes, also speaking to The Guardian, added.

“As far as we know, they’ve never suffered heat deaths before.”

And people say climate change isn’t real.

In January, hundreds of grey-headed flying foxes in New South Wales died when temperatures reached 44.2°C (112°F). According to local experts the bats effectively “boiled”, their brains frying thanks to the heat, causing them to drop from the sky.

"When you have temperatures 40 degrees and over, especially for the consecutive days, you will start losing bats. They can't sustain an internal temperature over 40 degrees exactly like humans can't – they just drop out of the trees dead and dying," Trish Wimberley of the Australian Bat Clinic told AAP. 

"All (volunteers are) seeing is hundreds and hundreds of dead bats of a species that is critically endangered, it's heartbreaking."

Some bats are being rescued and nursed back to health by volunteers and wildlife conservation groups, but they are asking people to get in touch if they come across fallen bats, and unless you are vaccinated or trained in animal rescue, not to touch the bats themselves.  

Any of the bat population potentially carries the deadly Australian bat lyssavirus, a rabies-like infection that can be transmitted by a bite or scratch. Only three people have contracted the virus in Australia since it was first identified in the 1990s, but all of them died. 

Wildlife campaigners have been lobbying the Australian government to upgrade the bats' threatened listing from vulnerable to endangered. Perhaps these extreme heat-stress events, exacerbated by climate change, that are causing animals previously unaffected to drop in the thousands will be the wake up call it needs.