Hundreds of bats have died following the extreme temperatures on the weekend.
Dead bats were found scattered on the ground and hanging from trees in Campbelltown, with a colony of bats near the train station collected by WIRES.
It is estimated that 204 dead bats were found, and most of those were babies.
It reached a whopping 44.2C in Campbelltown on Sunday, with temperatures over 42C considered to be fatal to bats.
“They basically boil,” Campbelltown colony manager Kate Ryan said.
“It affects their brain – their brain just fries and they become incoherent.
“It would be like standing in the middle of a sandpit with no shade.”