10,000 feet above sea-level, 15 swimmers push their bodies in sub-40-degree ice water for an entire kilometer (or six-tenths of a mile). No wetsuits, just a speedo, goggles and swim cap are all these competitors wear for South Africa’s national championships in the International Ice Swimming Association.

RELATED: How to survive a long-distance swimming challenge

Founded by Ram Barkai, the IISA is one of the coolest grassroots sports we’ve heard of (see what we did there?). More trying than a simple polar plunge, swimmers must complete the kilometer course which takes anywhere from 15 to 20 minutes — which, coincidentally is about all the body can handle of those temperatures.

RELATED: Short film about the world's best under ice freediver is breathtaking

Is this the next big thing in swimming sports? Maybe, but considering how extreme it is that remains to be seen. The precautions and training alone are enough to scare away even the strongest swimmers.

Fancy an ice swim?

Fancy an ice swim?

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