Back in 2013, creative director Adrian Ang and his then girlfriend - now wife - decided to climb up to Everest Base Camp.

For him, the journey up to the 5,380m point on the south side of Mount Everest in Nepal was physically taxing, but one he knew he wanted to cross off his bucket list.

"I've always enjoyed being around nature and, for me, climbing to Everest Base Camp was one of the things I wanted to do while I was still young and able," he says.

The duo made the 13-day milestone trek and have no regrets.

"It was really hard and we had some tough moments, but it was totally worth it. I would recommend the experience to anyone willing to step up to the challenge," says Mr Ang, now 30.

It seems that he is not alone in his quest to experience the literal high that comes with high-altitude trekking.

A report released last week by local travel agency Chan Brothers Travel flagged one big trend this year - Singaporeans blazing the trail in exotic locales such as Peru.

The South American country is home to ancient archaeological site and new wonder of the world Machu Picchu, which can be accessed at an altitude of 2,340m.

According to the trend report, another hot destination this year is the Taktsang Lhakhang or Tiger's Nest monastery in Bhutan, perched on a cliff 3,000m above sea level.

Ace Adventure Expeditions, which has been planning and leading mountain-climbing expeditions since 1999, has seen a steady rise in queries and repeat bookings for high-altitude endeavours over the past five years.

"We were seeing so many beginner trekkers that, this year, we started the Start Trekking programme, in which we handpick treks, well suited for beginners, which offer breathtaking scenery without being overly taxing," says Ms Vinnie Tan, 45, the firm's co- founder.

"The treks to places such as Inle Lake in Myanmar or to Mount Hehuan in Taiwan give first-timers exposure to trekking without a high risk of Acute Mountain Sickness, or AMS."

Their trips range from four days for treks in the region to 22 days for climbs up to Island Peak in Nepal.

But for Singaporeans, who are used to living 15m above sea level, these hikes can be a challenge.

According to Singapore Sports Medicine Centre sports physician Dr Roger Tian, AMS "usually affects travellers above 2,700m, but can start as low as 2,400m".

Symptoms of AMS are rarely life-threatening. They include headaches, shortness of breath while performing ordinary activities, loss of appetite, nausea, hallucinations, insomnia and general malaise. In rare instances, it can require a helicopter evacuation.

According to Dr Tian, travellers should "avoid intense exertion for the first 24 to 48 hours after arriving at altitude and consider taking acetazolamide, also known as Diamox - a prescription drug which speeds up acclimatisation and reduces the severity of symptoms".

Ms Pauline Tan, 49, Ace Adventure Expeditions co-founder, says the best way to avoid AMS is to acclimatise at the destination before starting on the trek.

She adds: "When the starting point for the trek is already at a point of high altitude such as in Leh, which at 3,500m is the starting point for treks in Ladakh, India, I recommend arriving two or three days in advance to give the body time to adjust to the lower oxygen levels."

Another trick is to "climb high and sleep low", she says, a method which entails climbing up to a point with a higher altitude and staying there for a short while before descending and sleeping at a lower altitude.

"It is a good technique to expose the body to higher altitudes for a short period of time," she adds.

For avid trekkers such as Ms Olive Poh, 34, who has been on three high-altitude treks in Nepal, India and Taiwan, training prior to the trip is key.

"AMS can hit even the fittest of trekkers, so instead of worrying about what might happen, I focus more on training to walk 8 to 10km a day, so that I am not overwhelmed on my trek," the dance instructor says.

"Besides ramping up my cardio, I also do a lot of strength training for two months before the trip to make sure my muscles do not get fatigued easily."

The best way to train for a high- altitude trek? Climb the stairs in high-rise buildings with a backpack and gradually increase the weight in your bag. This will enable you to carry the roughly 5kg daypack on your expedition, used to hold necessary items such as water and outerwear.

The stairs at Bukit Timah Hill is another popular choice for trekkers who are preparing for a high- altitude trip.

Still, even the best preparation may not be enough.

Ms Audrey Low, who has previously climbed Mount Rinjani and Mount Kinabalu, had to be evacuated off the Island Peak Mountain route in Nepal earlier this year, five days into her trek.

The 30-year-old, who works in finance, recalls being hit by intense headaches and insomnia on the third day of the trek, at a height of 3,600m. By the fifth day, she was vomiting multiple times. Her oxygen levels fell to 50 per cent, at which point her guide made the call to evacuate her.

"I wasn't expecting AMS as I had done some high-altitude treks in the past and never experienced it," she says, recalling feeling incredibly weak and disoriented.

"That's the thing about AMS - it is very unpredictable and can hit anyone regardless of fitness level."

As for Mr Ang, whose army boots fell apart during his descend from Everest Base Camp, it was sheer luck that got him through to the end.

"I ended up wearing sports shoes for the tail end of the trek, which was dangerous because they didn't have much grip or traction," he says. "My advice is to invest in good-quality equipment for your trip. Ultimately, that will keep you safe through your trek."

Still, despite the scare that Ms Low went through, she says she is open to possibly going on another high-altitude trek.

"It was a scary experience and I might just be more prone to AMS than other people, but there is still something that draws me to trekking," she says. "I might just attempt it again in the future."

Correction note: An earlier version of the story incorrectly stated that Pauline Tan is a member of the Singapore women's Everest team. This is incorect. She is not a member of the Singapore women's Everest team.