We’ve all heard stories of the weather-beaten 103-year-old Russians, who attest their longevity to regular swims in frigid waters. Although the evidence for cold-water’s effect on your lifespan is anecdotal at best, what is known is that nothing makes you feel truly alive like taking an alpine dip – and New Zealand has the best place to do it.

Just west of Makarora, in Mt Aspiring National Park, lies Crucible Lake, a crystal clear lake ensconced in the Mt Alba massif. Three sides of the lake are formed by the mountain’s flanks, which rise directly out of the lake for more than a kilometre. This quirk of topography means that even in the height of summer the water is dotted with icebergs, recently fallen from the glaciers above.

After a strenuous route to reach the lake, chances are you’ll be pretty hot and bothered by the time you get there. The trick is not to stop and think about it – just jump straight in!

Hitting the water isn’t what you’d call pleasant, perhaps the best description comes from Norwegian boat builder Ulf Mikalsen: “It’s like fifteen dogs and cats all biting at your feet”.

But when you step back onto the rocky shores of the lake, a tingling sense of warmth and wellbeing seeps into your skin. Just being out in the sunshine will feel like pulling on the puffiest down jacket in existence.