The big danger with hypothermia is that you don’t always realise you’ve got it until it’s too late. As blood is rapidly drawn to the brain and other vital organs, to keep them alive, you first lose coordination, then consciousness, then you die.
That’s if you’re not dead already. The bigger danger of subjecting the body to frigid temperatures - such as swimming in cold water of around five degrees - is a heart attack. Either way, not many people would survive longer than 45 minutes.
There is no fear of this among us Dry January Swimmers, a WhatsApp group set up at the start of the month after prophesying the unseasonably dry weather to come, and inspire us to greet the high tides and Goddess of dawn at Seapoint. At least at the weekend. We’re nearing the end now, and after steadily progressing from a few seconds to somewhere under a minute - or in some cases regressing - the experience has been comfortably numbing.
Others have endured longer than me. I am not the ice man, I am not the walrus, and typically emerge resembling the washed-up junkie corpse. Pinch me softly and I bruise, pinch me hard and I bleed, and with a body fat level somewhere around zero, cold water is merciless, but righteous. Which evidently is all part of the exercise.
It's been comforting too to observe the seasoned cold-water swimmers parading around afterwards in their branded Dry Robe, acting as if they're somehow related to Wim Hof, knowing I'll never be truly one of them. There are some measures of discomfort that will always be based around body mass index, even when trying to get high on your own supply, which is okay, because this is no contest, and just like the running and cycling numbers which soared during the pandemic, cold water swimming - not just in the sea, in the rivers and lakes and abandoned quarry pits too - is now the people's game.
There is also good reason why Wim Hof has fast become a hero to a great many of these people. No one will last long submerged in cold water if they forget to remember how to properly breathe, release the endorphins and adrenaline which come with it, which is essentially what his method is all about.
At 62, the Dutch extreme athlete better known as The Iceman also reckons his super-oxygenating breathing method, combined with a daily cold shower, can suppress inflammation, boost the immune system - possibly alleviate depression. There is no proof of that, only experience, which Hof has openly shared with the likes of Joe Rogan, as far back as October 2016, then Novak Djokovic and Russell Brand, making good sense it seems, though Neil Young might disagree.
Dr Wouter van Marken Lichtenbelt, the Dutch scientist at the Maastricht University Medical Centre who carried out tests on Hof in 2017, describes Hof's scientific vocabulary as "galimatias" only "without excessive expectations, it doesn't hurt to try." His method is certainly no pill, the cold showers certainly work for me.
As for the dangers of hypothermia, specifically when swimming in cold water of around five degrees, for up to 45 minutes, these are the exact conditions 25 people will subject themselves to in Saturday's 10th Eastern Bay Invitational International Ice Mile Swim at the Clontarf Baths in north Dublin.
This is no whimsical craze and definitely no contest, but a now established and internationally recognised event: wearing nothing more than standard swimming togs, a cap, and goggles, they'll swim for a mile (in this case 40 lengths of the 40-metre pool) and provided the water stays at five degrees, or less, and they survive within 45 minutes, they'll be rewarded with the title of International Ice Mile Swimmer.
It's all approved and supported by Swim Ireland, an extreme sporting event that is also "extremely dangerous", Fergal Somerville tells me, the now 58 year-old from Dublin and sort of Ireland player/manager of the International Ice Mile, who's been taking part since day one.
Clontarf Baths may contain sea water, and on the coldest of Dublin winter nights drop to 2.5 degrees, still the fear around the 2022 Ice Mile is that the water won't be cold enough. "This is the worst weather we've ever had for an ice mile," he says, "I was reading yesterday they'd sold out of snow boards in Jerusalem. Last week it was 5.6 degrees here, five degrees is the official mark, to register for an international ice mile, but there's nothing we can do about the temperature, so we'll still go with it, international ice mile or not. What's important is they get through, enjoy it, and can swim again tomorrow."
A member of the Eastern Bay swim team, Somerville has already completed several extreme open water swims (the English and North Channels, etc) yet this presents a uniquely testing challenge, which is clearly not for everyone. There is a 45-minute cut-off, the swimmers setting off in groups of five, across the five lanes, and checked at quarterly intervals: “If they’re not hitting the pace, they’re pulled out of the water. We’ve two ambulance crews, the same doctor who’s been with us all through, and safety is paramount, they have been preparing since October.
“A lot of them do look like death when they come out, are completely miserable, only for life to slowly return. None of us are going for the Olympics. The average age is 49, the oldest is 70, I’m 58, but you don’t just show up on the day. Nobody would survive that, no matter how much blubber they’re carrying.”
Over the pool wall, the seawater is a balmier seven degrees, the concrete basin of the baths lowering the temperature further. Somerville also runs the Dublin Cold Water Swimming group, from October through to the end of January, catering for what he sees as the fast-growing interest in the new people's game. "During the lockdown, people couldn't go anywhere, realised they were living five kilometres off Portmarnock or Bull Wall, wherever. Last year, I'd say the increase in sea swimming in Dublin was threefold, and it can be incredibly therapeutic."
As for the latest science behind it all, Steve Magness, the US author of Peak Performance, The Passion Paradox and The Science of Running, produced a lengthy Twitter thread earlier this month looking at cold water exposure from an athletic, health and well-being standpoint.
It seems ice baths and cold swims can aid the recovery process, only reach a point too when they inhibit it, and any immune or hormonal surges can be similarly replicated by sprinting up a hill, playing a video game, talking to friends, or walking in nature. “They are a tool,” he says. “They can ‘work.’ Many things can. They aren’t magical.”
Even if walking and talking, without the danger of hypothermia, is not the same thrill.