What does it take to climb the world's highest mountain? Reporter Fleur Cogle spoke to former Timaru woman Christine Burke, who spent four years preparing herself for the adventure.
Imagine trudging through bush, hauling a heavy backpack, weekend after weekend, year after year.
Sydney lawyer Christine (Chris) Burke didn't just imagine it; she committed herself to four years of intense training to ensure she was properly prepared to scale the world's highest mountain.
In the end, the challenge proved to be as much a mental battle as a physical one for the 42-year-old former Timaru Girls' High School head girl.
It's a coolish June morning and the students at Timaru Girls' High School are at assembly.
Chris, a slight woman, takes to the lectern and without much preamble starts sharing some anecdotes of her years at Girls' High, where she was head girl in 1986.
As she talks, slideshow photos flick over a large screen – mountain scenes, climbers, sherpas, tents, ice walls; it becomes clear why she has come to talk this morning.
"I climbed Mt Everest. It's something anybody could do but not a lot of people want to do because it's hard, it's uncomfortable; you don't get to shower for a long time and, if you do, you might be doing it with a bucket and a cup; you have to train, you have to give up seeing your friends for a long time because you have to spend so much time out in the bush."
During the four years she trained, she focused on rock climbing, abseiling, canyoning and trekking, she tells her audience.
"I would spend my weekends doing between 50 and 100 kilometres in the bush. Sometimes I would carry up to 30 kilograms on my back and I would just go up and down hills."
The photos are still turning over. Suddenly, a low peal of laughter spreads through her audience.
Somehow, Elmo, Sesame Street's iconic red baby monster, has made his way into the frame.
Yes, she tells them, Elmo has climbed Mt Everest.
Elmo, it turns out, is one of the tools she used to deal with the mental hardships on the mountain.
"I took Elmo with me to Everest because I thought he would keep our spirits high as we climbed – because morale is a very difficult thing when you're in a tent for a long time; you're cold, you're dirty, you're not getting the food you're used to. It can get very uncomfortable so mentally you have to be prepared for the hardships.
"Taking Elmo with me was brilliant because he's funny and every person I met laughed, and people wanted him in their photos."
Her talk to the students wraps up, but there's still more of her story to tell – quite a bit more.
An experience last October on Ama Dablam, another Himalayan mountain, brought home to Chris the need for mental toughness.
Before her trip she had a chest infection, which can become dangerous on a mountain. "I had diarrhoea at high altitude – which is entertaining in itself – and I just didn't feel I was climbing on my terms, so I turned before the summit because I didn't think I deserved the summit."
It was not her first brush with health issues at altitude; in 2009 she climbed too soon after having pneumonia and had to be taken off Cho Oyu, the sixth highest peak in the world, when she developed high altitude pulmonary oedema.
Her decision to turn back on Ama Dablam is one she struggled to come to terms with; in retrospect, she believes she made a mistake.
"I think I wussed out. I feel I copped out."
Mistake or not, the experience made her consider a new aspect of her training for Mt Everest: working on mental toughness.
"I knew physically I could do it; I didn't have any doubts – I had done the training, I knew I was strong and I adapted well to altitude.
"What I was less sure about as a result of the last mountain was whether I could deal with the politics and mental games that are played at base camp.
"A lot of people will try to distract you from your goals, subconsciously or consciously, and I had to prepare mentally to shut out out all the politics of base camp, all the competitiveness, anything negative, and just focus on the goal, and that was a big change for me in the last five months."
There was some pressure for companies to get teams to the summit, she said.
"Our team didn't buy into any of that. We focused inwardly and we supported each other.
"We know not every team had that because we would hear about their disputes and their fighting over food, and personalities conflicting."
Five months out from her climb, Chris added a new training component – working with a coach.
"She helped me mentally prepare by working through scenarios of what I would do if certain things happened on the mountain – illness, injury, morale changes, dealing with many different people, and how I would deal with success or failure on the climb."
The coaching was brilliant, she says. "On Everest, there was never a day when I thought I wouldn't do it."
Oddly, the lesson she learnt from the coach was about success: "[I learnt] pretty much that it's OK to succeed. I think I normally do things under the radar and my fear with Everest was that my photo might be in the paper.
"I had to learn that that is actually OK – that sounds silly – but that it would be OK."
Christine Burke's love of the outdoors was nurtured in her childhood, when she was growing up on Harper St in Timaru as the youngest of eight children.
"I always loved the mountains, living here. My mother and father were walkers, so every Sunday we were dragged on a walk with little legs, and then once we got bigger we were taken into the hills to go bushwalking."
After high school she went to Otago University to study law, intent on becoming a criminal lawyer.
She headed to Sydney when she finished her degree but returned to Timaru when a brother was killed in an accident. She ended up practising law with Timaru lawyer Morice Ward for a year. During that time she realised criminal law was not for her.
"When I was at law school I said I would never do property because I hated it, but then I worked for Morice Ward and he was so good at it, and he was such a good teacher."
A year later, in search of better weather and experience working in a large city, Chris went back to Sydney, where she has been ever since.
For the last 13 years she has specialised in property and development law – infrastructure, roads, bridges, tunnels, sale and purchase of large commercial industrial buildings, construction of buildings, and project management of property construction.
"There are lots of parallels [between law and climbing] and a lot of people have said that to me: that law requires commitment, long hours, dedication, sacrifice, hardships; it's not all beer and skittles."
As it turns out, Chris may have been born to climb. She knew she needed to find some form of fitness to take up. At first she thought she would be a long distance runner, but after injuries she cast about for something else to do.
She had been trekking in Nepal and decided to try going "a bit higher". Doing so she realised something: "there's only a small percentage of people that can adapt to altitude well; it seemed that my body adapted well."
People who produce red blood cells quickest are better at going to altitude and she seems to fall into that small group of 3-5 per cent of people, she says.
"People who don't acclimatise quickly, they get migraines. I have never had an altitude migraine and people can't figure out why."
Not for lack of trying. Before she left for Nepal, the New South Wales Institute of Sport did testing on her, putting her on machines as they tried to figure out what part of her body gave her the ability to acclimatise quicker.
"The chap didn't come up with the answer because I didn't have time to go back and do more before I left, but he thought that because I don't have the world's best circulation, because my blood was passing the lungs slower, that it was picking up more oxygen."
Climbers have two windows of opportunity in a year – April/May and September/October – to climb Mt Everest, which rises 8848m between Nepal and Tibet.
On May 20 after years of hard work, within sight of the summit – and in the death zone above 8000m, disaster struck: she started having problems breathing.
"The mask was sticking to my face and I thought, `I can't believe that I'm at 8700m ... I'm nearly there and I'm going to have to turn around [because] something is wrong with me'."
For six painful weeks up to this point, her climbing team had been moving up and down the mountain, acclimatising, the pressure of the altitude making their bodies hurt.
After weeks of gradually moving to higher and higher points on the mountain, Chris's team made a four-day push for the summit.
"You spend a lot of the time on the mountain climbing in the dark. It wasn't uncommon that we would get up at midnight or two in the morning, and we would start climbing an hour or so later. We would have a head torch and we'd spend the next 10 or so hours climbing and then we would climb through the day."
There wasn't a lot of sleep, "but at altitude it's very hard to sleep anyway because of the lack of oxygen".
When her breathing problems developed, memories of Ama Dablam were fresh in her mind: "I thought, `here we go again'."
She yelled out to a sherpa.
At first, they couldn't find the problem, but growing more concerned, they searched again.
A large chunk of ice had formed on her air release valve. She had been unable to see it because of the mask and "Michelin"-sized suit she was wearing.
Oxygen tanks are not made for altitude, she says.
Aware of the issue with her tank, she was able to deal with it when the situation arose again – enabling her to reach her goal.
"I managed to make the summit [at 9.30am or 3.45pmNZT]. When I actually got there, the other three in our team, they cried, they were very emotional and excited ... but I got there and I kind of just sat down and looked at the view.
"My sister made a joke that it's because we have mountains, it was just another mountain – I was really excited but I think I was so relieved that I just sat there and thought, `wow, what a really cool view'.
"The big thing for me on this mountain was I didn't give up; I was happy if I had to turn around because of the weather – that would have been fine – but if I turned around because I was a bit tired, or I wanted some water, or it was just too hard, I wouldn't have accepted that this time, because I have turned around once before."
Climbing Mt Everest is not cheap. Every Western climber must have a US$10,000 permit to climb, then there are the fees charged by the climbing companies. The most expensive guiding companies can charge up to US$65,000. Cheaper deals (around US$30,000 to $40,000) are available.
It cost Chris US$54,000 – a sum she had set aside for a couple of years and money well spent for her, she said.
"I think some people buy cars; I don't have a lot of material possessions – I've always said I want to do things, not have things."
Mountaineering, she said, was 60 to 70 per cent mental strength and being able to deal with the challenges you come up against in the mountains.
"Not everyone can, or wants to deal with these things."
So what does the future hold for the fourth New Zealand woman to summit Mt Everest?
Despite the years living overseas, Chris frequently returns to Timaru to see her family – and likes to make an annual trip to Aoraki/Mt Cook.
However, she has never climbed New Zealand's highest mountain.
"Mt Cook is next on the agenda. I'm getting some resistance from different quarters, not because of its difficulty but because of the fact that she can be unstable. I have purposely left climbing her until after Everest because I think growing up in her shadow you know every accident and tragedy and I think that's what's bothering friends and family."
After that there are more climbing adventures – and, she hints, possibly a world-first attempt which she is considering.
She may have to get used to having her photo in the paper.