There was a distinct greenish tinge to Herald travel editor Winston Aldworth as he slumped at his desk at midday last Friday.
After at least three drinks too many at an airline function the night before - including a most unwise brandy and ginger ale nightcap - he's battling a "mighty" hangover.
Forty minutes later he's a new man - well almost.
"I feel great," he says heading back to work after a 20-minute hangover treatment at Spaqua, New Zealand's first oxygen bar.
After downing a can of liquid labelled Alcohol Killer, he spends the next 20 minutes inhaling enriched oxygen, which has been passed through winter green and lime aromatic solutions, through a nasal tube.
When he combines the two they smell of linament, which he likes as it reminds him of sporting glory days long since passed. The whole package costs him $20.
"I did feel a bit of a plonker at first, sitting in a shopping mall with green tubes up my nose," he admits.
"I was sceptical, but genuinely feel better after trying it. It could be a placebo effect - maybe I imagined the recovery. I was deliberately breathing deeply throughout, so that presumably helped as well. But whatever it was, I felt heaps better at the end than I did when I sat down."
Georgina Davies turns up just as the Herald delegation is exiting the Downtown Mall-based establishment. The 37-year-old is a repeat customer, having first hit the oxygen bar a week ago.
"It's great, it definitely gets rid of headaches," she said. "I felt great afterwards, had a lot of energy. I had a bit of a cold as well and it cleared up my nose. I've come back because I've been over in Australia and I'm still a bit tired and jet-lagged from that."
Partners Emma Leslie and Evan Seber staggered across an oxygen bar in Las Vegas, and decided to bring the concept - which has been around since the late 1990s - to New Zealand.
"We'd had numerous big nights, as you do," Ms Leslie said. "We hooked on to these oxygen bars and just felt amazing afterwards."
The benefits of inhaling at the bar for $1 a minute include increased energy, improved endurance, pain relief, increased stamina, reduced stress, enhanced performance and headache relief, claims Spaqua's promotional material.
"First of all, none of that is true," says Dr Kyle Perrin, a senior lecturer at Otago University who researches oxygen therapy for medical use. "Secondly, it is potentially quite harmful."
Excess oxygen was dangerous for people with serious lung disease, or who have suffered heart attacks, Dr Perrin said.
Normal air contains about 21 per cent oxygen. The oxygen bar pumps it out at around 95 per cent.
"Your body is attuned to breathing room air and that is as much oxygen as we need," he said.
The body's haemoglobin would be almost 100 per cent saturated with oxygen just by breathing normal air.
"By breathing more oxygen you can dissolve a little bit of extra oxygen in the blood but that provides no benefits whatsoever to your health. In some situations, in people with respiratory diseases, it can be quite harmful."
Excess oxygen could cause carbon dioxide to build up in blood, resulting in drowsiness.
"If you are in hospital and you are very unwell you can die from too much oxygen. If someone had severe lung disease and didn't know it was risky or harmful and just wandered in off the street and were given high-concentration oxygen there are potential harms to their health.
"One of the things that we tell our staff in hospital is that oxygen is a drug. It is prescribed for specific conditions and should be given at specific rates. Generally, it is used only for people who have low oxygen levels."
Spaqua claims that the benefits of oxygen therapy will be felt hours later, particularly in the afternoon, when many of us typically hit the coffee shop or vending machine for a pick-me-up. A morning session at the oxygen bar will take care of that, the company claims.
Dr Perrin isn't impressed.
"There's absolutely no way there would be any prolonged effect from it. There's no physiological way that could ever occur. As soon as you take those prongs off and walk away, within a few breaths your oxygen levels are back to where they were before.
"All of their claims about the health benefits of oxygen, I'd consider to be completely unsubstantiated, and it's somewhat concerning actually that they've been able to do this."
Spaqua's clients, who include fitness buffs who come in pre-work out, students wanting a brain boost before exams and even competitors from the BMX world champs seeking a pre-race edge, disagree, says Ms Leslie - although passers-by do question the concept.
Several hours later, Aldworth is at his desk, revitalised, and impressed with the effects of the hangover buster.
"I had a mince and cheese pie afterwards," he says. "That was pretty damn good too."
Worse-for-wear customers noticed the most pronounced benefits, but the company didn't want to be thought of as just a hangover bar, Ms Leslie said.
"There are so many different benefits."
More Aucklanders will soon be able to test that claim for themselves. The company plans to open a bigger bar at a second - still secret - location soon, and will be offering national franchising opportunities.
Dr Perrin certainly won't be visiting if an oxygen bar opens up in his neighbourhood.
"Oxygen should be considered a drug and they are dispensing a drug in a slightly haphazard fashion."