Mr Moir was addressing the court when he stopped mid-sentence and sat down.

He was assisted from the courtroom and taken to John Hunter Hospital by ambulance.

It was the second successive day that the courtroom's air-conditioning did not operate.

Pedestal fans were again used in courts 5 and 6, but the sweat poured from lawyers, court staff and packed public galleries.

Newcastle Bar Association president Peter Harper said conditions in the court were "beyond tolerable" and the time for protests and picket lines was approaching.

"The staff and lawyers at the courthouse do an amazing job to ensure that the criminal justice system functions efficiently," Mr Harper said.

"There would always be a reluctance to disrupt that, but one wonders if we're approaching that stage where such action needs to be taken."

The association will lodge an objection with the Attorney-General and is considering contacting WorkCover to assess the courthouse, Mr Harper said.

"It's now an issue of occupational health and safety for court staff and other court users," Mr Harper said.

"It beggars belief that O H and S legislation that was introduced by the Government doesn't seem to apply to a government building."

Solicitors and barristers were once again invited to take their jackets off in court yesterday and magistrate Elaine Truscott did not wear her robe.

A spokeswoman for the Attorney-General said technicians worked into the night to fix the air-conditioning.

"The original fault was repaired," the spokeswoman said.

"A subsequent failure resulted in the system again shutting down in courts 5 and 6 later on Tuesday morning."

Newcastle MP Jodi McKay said the courthouse was inadequate and a new justice precinct was needed.

"This is clearly unacceptable and I would expect technicians to be working around the clock to fix the fault," Ms McKay said.