On a night of mass drug overdoses at a Melbourne music event, it's "good luck rather than anything else" that no one died.
Paramedics treated 25 people at the Electric Parade Music Festival at the Sidney Myer Music Bowl on Saturday night, with most of them taken to hospital in a critical condition.
Ambulance officers also treated seven others who collapsed in nearby parks and streets.
Ambulance Victoria state health commander Paul Holman said the event was "awash with drugs" and there was a serious risk of death.
"That we haven't seen that tonight is probably good luck rather than anything else," he told reporters early on Sunday.
The danger many put themselves in was self-inflicted and had a "significant impact" on ambulance resources, he said.
"It's the highest number of overdoses we have seen at a music event for some time."
St Vincent's Hospital took eight patients and most had GHB and "a cocktail of other drugs" in their system, its spokesperson said.
By 9am on Sunday, seven had been discharged and the one remaining was not in a critical condition.
The Alfred took in 15 drug overdose patients - two were critical but the majority had been discharged.
The majority of the drug overdoses are believed to have been of the synthetic drug GHB.
"It's a drug that causes people to become unconscious, slows the heart rate and can cause seizures," Mr Holman said.
Days before the festival, Electric Parade organisers cautioned attendees about "zero tolerance" of drugs.
"Anyone caught using illicit substances throughout the event will be swiftly ejected by security and will not be allowed to return," it said on its Facebook page.
The Royal Melbourne Hospital also treated overdose patients, though its figures are yet to be updated.
The event is scheduled to be held in Sydney on Sunday.
Police say 40 people were arrested at the event.
One man was charged and remanded overnight after quantities of ecstasy, cocaine, MDMA, LSD, ketamine and hash were found on him.
