KEY POINTS:
A fisherman whose two friends died from carbon monoxide poisoning in a small cabin has been transported back to the Navy Hospital for treatment.
Waitemata District Health Board spokeswoman Bryony Hilless said the man was in a serious condition.
She said he had returned to the Navy Hospital for oxygen treatment in a hyperbaric chamber, a treatment used for people with the diving sickness, the "bends".
Earlier this morning he was at the North Shore Hospital where he was reported as being awake but causing hospital staff "some concern".
The Waikato man could spend another two days on the North Shore before being transferred back to Waikato Hospital, depending on his condition, Ms Hilless said.
The man could have been saved because he fell from a top bunk in the cabin which allowed him to avoid the fumes caused by a charcoal barbecue the friends had brought into the hut for warmth. He survived by breathing air through a crack in the door.
Police told the Herald this morning that the two men who died were a 35 year-old store manager from Howick and a 50-year-old store purchaser from Hamilton.
The overnight fishing trip to a remote west Waikato beach while their partners held a baby shower in Hamilton seemed a happy arrangement for five friends on Saturday night.
The group from Hamilton and Auckland - four men in their 30s and the teenage son of one of them - booked two small cabins in the Ruapuke Beach Camping Ground, 20km south of Raglan, cooked a meal on the charcoal barbecue and had a few drinks.
Three men in one of the cabins planned to go fishing on the Papanui Pt rocks at 5.30am and the father and son in the other cabin were to join them later.
"Eight o'clock in the morning the little fella came and said, 'I want something to eat but I can't get into the cabin - they won't answer'," said the camp's resident caretaker, Ben Walker.
"I thought, 'Why aren't those guys in there talking?' and then the boy's father said, 'Where is the barbecue?' and then I thought, 'Oh no. They've taken it in with them.'
"I had a key but could not get it in the door - they had snibbed it.
"So I got the drill for a hole to open the window and then ... Oh gee.
"One of them, Jason, was lying on the floor against the door. I heard him say he had passed out and he could not move.
"The boy's father pulled one of them out of the bed and one of my mates went in and got the other one from the bunk ... I didn't let the young fella see inside."
Mr Walker believed that Jason, who had stayed at the camp before for the fishing, had fallen from his bunk against the door and had his nose at the crack under the door.
"He must be as tough as nuts."
Mr Walker said he had talked and joked with the group on Saturday night.
"They are from South Africa and we talked fishermen's lies and I kidded them about losing the rugby to us.
"They were happy-go-lucky, going fishing, here just for the night and then back to town.
"They were here because their partners were holding a baby shower for one of the women who is expecting a baby soon.
"The boys must have had a few beers and drifted off to sleep and that's it.
"What can you say? It's just an unfortunate accident. They didn't realise what they were doing when they took the barbecue inside.
"It's too small in these cabins to take anything in. It's just a silly thing that happened."
Mr Walker said he had always feared guests going fishing would be washed off the rocks by rough seas but never thought a barbecue - small enough to put your arms around - would be a lethal object.
The 32-year-old Hamilton man who was found on the floor was taken by the Westpac Air Ambulance to Waikato Hospital.
Police yesterday investigated the deaths at the camp, although Sergeant Brent Wallace of Huntly said they were not suspicious.
The cause of death would be ruled on by the coroner.
"Initial indications are that both men died as a result of lack of oxygen caused by use of a charcoal barbecue-type cooker in the enclosed room.
"They had used it for cooking a meal outside earlier on ... They have been cold in the night and used it to keep warm.
"It's a tragic accident. It obviously promotes the fact that you should not burn any fuel inside a closed room. There were no windows open."
Mr Wallace said the third man in the cabin was suffering from carbon monoxide poisoning.
It was thanks to the efforts of the man from the other cabin that "there's not a third death".
"It was fortunate that he fell on the floor where gas levels were not so high."
The Herald's Martin Johnston explains how carbon monoxide poisoning can kill:
Carbon monoxide poisoning kills by depriving the body of oxygen.
A colourless, odourless, tasteless gas, carbon monoxide can be produced by incomplete burning of fuels.
It can come from camping cookers used where there is not enough oxygen for complete combustion, and from car exhausts.
In the blood, oxygen is carried around the body by attaching to a protein called haemoglobin. But when carbon monoxide is inhaled into the lungs, it attaches to the protein, preventing oxygen from doing so.
This deprives organs, most importantly the brain, then the heart, from receiving the oxygen they need to function and survive.
A low level of carbon monoxide poisoning can produce a headache, but larger amounts can lead to unconsciousness, the heart ceasing to beat, and death.
"You can get significant brain damage that's very similar to brain damage caused by running out of oxygen," Dr Les Galler, an intensive care specialist at Auckland City Hospital, said last night.
The treatment involves oxygen therapy: either high-flow oxygen through a mask at normal atmospheric pressure, or being put into a hyperbaric chamber at increased pressure.
