A 22-year-old Queensland man was taken to Gosford Hospital on Saturday night after attending the Lost Paradise Music Festival at Glenworth Valley and died a short time later.

A man and woman also remain in a stable condition after ingesting an unknown substance and becoming sick at the event, which was advertised as drug-free.

Meanwhile in Victoria, two men were hospitalised after suffering drug overdoses at Beyond the Valley music festival over the weekend.

Paramedics were called to the event in Lardner about 7am on Monday and transported a man in his 20s by air ambulance to The Royal Melbourne Hospital in a critical condition.

A man in his 20s at the same festival was taken to Dandenong Hospital and treated for a drug overdose on Sunday morning.

NSW police have urged festival-goers to avoid drugs or face the consequences ahead of Sydney's Field Day, held in the Domain on New Year's Day.

"Those thinking of bringing substances into the event are reminded there will be uniformed and plain-clothed police patrolling the festival, which will include the use of drug-detection dogs," Detective Chief Inspector Stuart Bell said in a statement.

Last year 160 people were charged with drug possession at the event.

Three people have already been charged with drug supply. A 21-year-old man was allegedly found carrying 105 MDMA pills, while a 23-year-old was allegedly caught with 80 MDMA pills and six bags of cocaine.

The latest death has again sparked debate about pill testing, to which the NSW government remains opposed.

Labor leader Michael Daley is open to the idea and has re-committed to a "drug summit" to consider available advice.

He says massive police numbers and significant seizures at Gosford failed to prevent the death.

"Despite the best efforts of police, parents and school teachers who say 'don't do it', they're still doing (drugs) en masse," he told ABC.

"If you're going to ask experts and the wider community to have a discussion, you've got to talk about all of the options available."

Sydney Lord Mayor Clover Moore said pill testing was "practical, sensible" and in a similar category to safe injection rooms.

"We should do what we can to keep young people alive even if they're at a time of taking risks with drugs," she told reporters.

The organisers of a third event, Falls Festival, on Sunday afternoon issued a warning to attendees regarding a "dangerous orange pill" currently in circulation across Australia.

The weekend's death follows three others from suspected overdoses at NSW festivals earlier this year.

The state government announced new licensing regulations to combat the issue but they won't be in place until after the summer.

It also proposed up to 25 years' jail for drug dealers if one of their customers die.

Australian Associated Press