A 21-year-old man is on life support and would have been dead had it not been for the extra safety measures put in place at three music festivals over the weekend, the NSW government says.

NSW Health Minister Brad Hazzard revealed on Monday that 25 people aged 16 to 25 had been taken to hospital, 14 of them requiring "extremely high-level" care.

Revellers at the Electric Gardens music festival in Centennial Park on Saturday. Credit:Brook Mitchell

The 21-year-old was at the Hardcore Till I Die festival at Sydney Olympic Park on Saturday. He remains in ICU at Westmead Hospital in a "serious but stable" condition.

"This tells us … that we have a very serious problem, young people are continuing to take drugs and at such a level we had to get 14 receiving extremely high-level response," Mr Hazzard said.