Hundreds of bats 'boil' alive and drop from trees in brutal NSW heatwave

WARNING, DISTRESSING IMAGES: Hundreds of dead bats have been found scattered along the ground in the wake of the brutal heatwave that swept across Sydney and much of the country this past weekend.

The animals, many of them just babies, fell from the trees in the Western Sydney suburb of Campbelltown after the temperatures exceeded 45C in the city's west and other parts of the state.

“They basically boil,” Campbelltown colony manager Kate Ryan told the Camden Advertiser.

“It affects their brain – their brain just fries and they become incoherent."

She said there were at least 200 flying foxes found on the ground but hundreds more were still dangling dead from the trees.

“It would be like standing in the middle of a sandpit with no shade," Mrs Ryan said in the post on Help Save the Wildlife and Bushlands in Campbelltown Facebook page.

“I don’t know how many times I bent down and got on my knees to pick up a dead baby.

“There were dead bodies everywhere.”

Confronting images shared on Facebook revealed just part of the horrific extent the heatwave had on the colony.

"There were tears shed and hearts sunken, it's devastating when a colony like our local one goes down like this due to heat, this colony needs more canopy cover and shaded areas to help with our ever rising hot summers because this episode will surely not be the last," the post read.

Meanwhile, Sydney has gone from one weather extreme to another with fierce thunderstorms rolling over the city in the wake of the weekend’s brutal heatwave.

More than 4600 lightning strikes were recorded between 3am and 6am in the greater Sydney region, the Sydney Morning Herald reports.

The SES were inundated with calls as heavy rain and lightning battered the city overnight, leaving homes without power and branches scattered across roads.

Further storms are expected across the state on Tuesday, with the Central Coast expected to feel the full force of the storm cell’s damaging winds.