The woman in her early 20s was sitting in a car at the Caltex service station on the corner of High and Oak Streets just before 1pm when she stopped breathing.

Her boyfriend ran into the service station shop shouting "quick help me, she's dying". 

The service station attendant ran out to find the woman unconscious in the passenger seat. 

He and the woman's boyfriend called for more help and a tradesman came over.

The tradesman, who is also a CFA volunteer, saw the woman was pale in colour. 

The three men lifted the woman out of the car onto the pavement and the tradesman began performing CPR.

The tradesman said the woman was "absolutely blue" when he began performing CPR, but he noticed her colour returning as he continued.

He told the Bendigo Advertiser he could hear the woman's ribs cracking as he pushed on her chest. 

During this, people at the scene spotted an ambulance driving past and hailed it with loud shouts and waving. 

The ambulance drove over and was soon joined by two other emergency vehicles called to the scene. 

The woman stabilized once paramedics gave her oxygen and she was taken to Bendigo hospital about 1.30pm. 

Bendigo Health confirmed the woman spent a night in hospital and went home on Friday morning.

The tradesman said he doubted his ability to help the woman for the first 20 seconds, but once he confirmed there was no breathing or pulse he sprang into action.

"If somebody's dead, you can't make it worse," he said.

He does not wish to be named because he believes every CFA volunteer would have done the same in his situation. 

The tradesman said his last refresher CPR course was eight months ago, but it was a British Heart Foundation advertisement he recently saw on youtube that helped him remember what to do. 

The 'Vinnie Jones Staying Alive' clip, above, is a educational and entertaining video that says anybody can do CPR.

"Hands-only CPR, it's not as hard as it looks," a character in the advertisement says. 

The tradesman said the people involved in Thursday's incident should be commended for the way they responded, especially the Caltex shop assistant. 

"He controlled the situation well," the tradesman said. 

Shop assistant Samthosh Pulluru said he was paranoid during the incident.

"I have never been in this situation before," he said. 

"I didn't know what I was doing for a couple of minutes."

Mr Pulluru said he tried to comfort the woman's boyfriend, gave him water, told him to sit down and that everything would be okay.