“Choose one that is shaded, that goes near a stream so you can always get water, and one that is near civilisation so you can get out quickly if you are in trouble,” says Sargent. “I wouldn’t do an isolated hike like [that to] Plover Cove [Reservoir in the New Territories] in the summer.”

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For those worried about germs or impurities, there are products that allow hikers to filter water from streams, such as the LifeStraw personal water filter (available from APA Outdoor Shop and Lantau Base Camp or the Grayl Ultralight purifier bottle (available from Waterlinks).

Stone Tsang Siu-keung, a paramedic and one of Hong Kong’s top trail runners, says you can get used to the heat but not the sun’s ultraviolet rays, so he also advises hiking on shaded routes.

“If you are training you may need to go to the top of a mountain,” he says. Because peaks are often exposed, Tsang suggests scaling the top quickly to get back onto shaded trails below.

2. Stay cool – in streams, with ice

Trail running coach Andy DuBois says there are misconceptions around heatstroke. Most people assume heatstroke occurs when you’re dehydrated, but it has to do with core temperature, which does not always correlate with drinking.

“The first thing you need to look at is cooling,” he says. “First, start cool, maybe consider putting on a top that has been soaked in iced water.”

Tinworth, co-founder of RaceBase, advises that you plan to pass large bodies of water you can submerge yourself in, not just drink from.

“The easily accessible rock pools, reservoirs and streams of Hong Kong are ideal locations to stop for a cooling dip mid-run in these hotter months,” he said in a blog post.

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Even Tsang, who competes in ultra-distance races across hundreds of kilometres, says he needs to soak in streams and rivers during Hong Kong summer runs.

Sargent, Mak and DuBois all advised freezing a bottle of water that will help keep other liquids in your pack cool as the water melts. You can also use it to press against your head, armpits or wrists to cool down.

3. Quench your thirst

Listen to your body, particularly when it comes to thirst. Tsang says if you feel dizzy, sit in the shade and drink water.

Tinworth points to the work of Tim Noakes and his book Waterlogged.

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“The reality is you don’t need to be told when and how much to drink,” the book says. “We have a 300-million-year developed system that tells you with exquisite accuracy how much you need to drink and when you need to drink. It’s called thirst. If you rely on thirst, you won’t ever become dehydrated, and you won’t ever become overhydrated.”

In 90 per cent humidity, you want to make sure you are able to answer thirst’s call by having enough water available. A good rule of thumb is to carry a minimum of one litre of liquid for every hour hiking. To avoid carrying more than you need, refer back to point number one and plan a route that passes near shops or streams.

4. Go early, or late – and go slow

The easier way to avoid problems with the heat is to avoid the afternoon sun, but in Hong Kong it is still hot even when the sun isn’t out.

The sun can have more of a jarring effect early in the summer when you haven’t had time to acclimatise, so don’t go on big all-day hikes through the beating mid-afternoon rays just yet. Instead, go early in the morning, late afternoon, or even at night.

Tinworth says that generally it can take two weeks of training in the heat to provoke the necessary changes in your body to deal with the heat. So build up to longer distances and efforts slowly.

DuBois warns that just because you are able to adjust to the heat does not mean you become immune to it.

“You will never be as fast in the heat,” he says. “You just have to accept that and go slower or risk overheating. Don’t get frustrated, just forget those winter times and readjust your expectations.”

Sargent adds that you should enforce rests. Even if you are feeling fit, take a break to avoid getting to the critical temperature. Rest before you need to.

5. Dress for the occasion

It may sound like common sense, but too often, wannabe hikers are seen melting as they clamber up The Twins (two peaks on stage 1 of the Wilson Trail, a popular hike between Wong Nai Chung Reservoir and Stanley on Hong Kong Island) in a pair of jeans.

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Mak recommends comfortable clothes and appropriate footwear for your summer excursions. She includes on her list of must-haves sunglasses, sun lotion and a hat or visor.

Tinworth advises against wearing cotton, as it holds sweat and will not dry quickly. Instead, wear loose sportswear in moisture-wicking, quick-drying fabrics.

6. Don’t forget your dog gets hot, too

Sargent recalls having to carry a dog up a big hill when the heat became too much for it.

“You forget how hot the ground is because you’re wearing shoes,” he says. “But if you’ve got a small dog it is so close to the ground it overheats.”

Sargent dunks his dog in water before he even leaves home, and avoids walking him during the hottest hours of the day.

Make sure you bring a small bowl so the dog can drink, and account for the pet when deciding how much water to carry.