Video·1 min read·June 2026

Cold Water Immersion: The Expert's Perspective

Professor Mike Tipton—one of the world's leading researchers on cold water immersion—on safety, adaptation, and what the science actually supports.

▶ Watch on YouTube

View transcript

Cold Water Immersion: The Expert's Perspective: Full Transcript

0:00

Welcome to the Happier Life Project, the official podcast from the award-winning mental health and wellness app, My Possible Self, hosted by broadcaster and journalist Gabby Sanderson. Hi, how you doing? I hope you're well. Welcome to today's bonus episode of the Happier Life Project. Cold water swimming, sea dipping, ice baths. It feels like everybody's talking about the

2:00

cold shock response, and the potential mental health benefits associated with this trending practice. We also talk about safety, breath work, and why research is still needed before we can take every viral claim at face value. So whether you're a seasoned sea dipper or just cold curious, get ready to find out the truth about cold water therapy. What's hype? What's helpful? and what

4:00

below the surface of the skin you've got lots of cold receptors. We're a tropical animal. We want to be naked in air at about 28 ° C. So going into cold water is particularly stressful and those receptors get stimulated particularly in the first seconds and send a lot of information centrally and that results in what we called back in the 1990s the cold shock response and it starts with a gasp of about 2 L which I'm sure you

6:00

love it and they're almost addicted to doing it. It's like a real adrenaline rush, I suppose. And then there's people like me that are not so fond of being freezing and putting that shock to the system just doesn't really seem very appealing. I'll stick to my yoga, you know. Yeah. Well, I mean, there's a few things you said there which are absolutely true. Most, as I say, we're a tropical

8:00

changed their life. Mostly it's mental health rather than physical health improvements. uh in fact I think it's only the sort of over 65s who start start to talk about it making them feel a bit fitter. The science on the kill side of the equation is very much better and more definitive than that on the cure side. Quite a lot of the stuff on the cure side of the equation is anecdotal. You know people asking people

10:00

it's that sudden fall in skin temperature that drives all those neural and hormonal changes that may well be the benefit of what's good about it. We know the cold shock response peaks somewhere between 10 and 15 ° C and we know that it only lasts a couple of minutes. So actually going into much colder water or going in for much longer, I don't think is of any benefit whatsoever. You're just moving more and

12:00

that's where if you exercise, you can probably maintain body temperature. Once you drop down into the below 20 into the teens, that's when you get I mean sea temperature in the middle of summer in around the British Isles might get up to 17 or 18. And you know, it's the old saying, it's okay once you're in. And what that actually means is it's okay once the cold shock response has gone away.

14:00

then uncontrollable hyperventilation. As you go in more times, you begin to get more control of your breathing or you get control of it sooner. Now when you go as I say most of the evidence in favor of that this approach whether it be the Wimhof method or ice dipping or cold water is anecdotal. The scientific data are at best mixed generally of poor quality because they haven't managed to have a proper control or there's been a

16:00

I would say the jury is still out. However, going back to my what I was talking about in terms of talking people who do it to some extent, if somebody thinks it's changed their life and is doing them good and improved their mental health and it has improved their mental health, then so what? You know, okay, that's fine. All I'm saying is two things. Firstly, as a scientist, I want to know the method and the mechanism by

18:00

response. That's the fight orflight response. That's adrenaline, nor adrenaline, cortisol, all these different hormones being released. You'll then have the I haven't had a cold for a year since I've been doing open water swimming. And I've not heard that one. Okay. Yeah. So, we've done studies where the trouble is you can look at the the cells of the immune system and you can

20:00

paper you read, Gabby, in this area has the caveat at the bottom which says more studies done that need to have larger numbers, more reasonable sample sizes, better controls, um, and less chance of bias. M well and also because you've mentioned a couple of times about this where the sort of temperature waters some in warmer some in colder and it seems quite similar and I would say well we're made up of a lot

22:00

know, are putting themselves at unnecessary risk. Um, so really what we want to ask is, you know, if you took up yoga or if you took up soccer or if you took up hill walking or beach walking, would that have the same impact? And those just studies just haven't been done. Well, as we kind of wrap things up, I think like the takeaway for me is that what you're saying is when we're looking

24:00

Society, the National Water Safety Forum, all of which have websites that you can go on and get information about how to do this, how to do it safely. If you go on to the University of Portsmouth website, you'll find the papers that we've published on exactly the same thing, you know, minimizing the risk in doing this. and you'll be kept updated with the latest research. So, um there are quite a lot of webs there's

26:00

are most active on Instagram and you can find us @ mypossible self and I've been @ radio Gabby. Until the next one, do take care. Bye for now.

Transcript auto-generated by YouTube. Verbatim — duplicates intentionally preserved.

Key Insights

Acclimatization is real but takes consistent exposure over weeks

Cold shock response diminishes with habituation—this is trainable

Safety protocols matter: gradual entry, supervised practice, medical screening

Benefits are dose-dependent: temperature, duration, frequency all interact

"The body adapts to what you consistently demand of it—controlled stress builds resilience when applied deliberately."

Wim's Wise Words

A second take, from someone who's lived it.

🧊 Wim's Wise Words

Bonus: The Truth About Cold Water Immersion, According to Science with Prof. Mike Tipton

What Tipton Is Really Saying

Professor Mike Tipton has spent decades studying what cold water does to the human body — not as a wellness enthusiast, but as a physiologist trying to understand why people die in it. That context matters. When someone with that background talks about cold water immersion, you listen differently than you do to the influencers in their ice baths.

His core argument is deceptively simple: the cold shock response is real, it's the mechanism that drives most of what you feel, and it peaks at 10 to 15 degrees Celsius and lasts only a couple of minutes. Everything after that — the longer sessions, the colder temperatures — isn't adding benefit. You're just accumulating risk. The signal has already been sent. Your body heard it.

Where the Science Is Honest

What I appreciate most about Tipton is his willingness to say out loud what a lot of researchers won't: the evidence on the "kill" side of cold water immersion — the physiological dangers, the cold shock drowning risks, the cardiovascular load — is far more definitive than the evidence on the "cure" side. Most of what people report as benefit is anecdotal. Life-changing experiences, yes. Controlled, replicated, peer-reviewed outcomes? Much thinner.

This aligns with what I see across the knowledge base. The 2018 CWI and athletic wellness paper shows real sprint performance improvements and fatigue reduction after cold immersion. The 2024 global cold water swimming review points to genuine cardiovascular and respiratory adaptations. But the mechanisms are still being worked out. We know it does something. We're still learning exactly what and for whom.

The science on what cold water can kill is clear. The science on what it can cure is still catching up to the claims.

Acclimatization Changes Everything

Here's the piece that gets lost in most cold exposure conversations: you are not the same person after six weeks of consistent cold water exposure. Cold acclimation can reduce the cold shock response by roughly 50 percent through repeated exposure. That initial gasp, the racing heart, the panic breathing — it diminishes. Your nervous system learns. The threat signal quiets.

This is not willpower. This is biology. The same receptors that fire with that first shock become less reactive over time. You're not toughing it out. You're training a physiological response, the same way you train anything else.

The Practical Protocol

Given what Tipton lays out, the recommendation is clear: gradual entry, supervised early practice if you're new, and short exposures in the 10 to 15 degree range. You don't need ice. You don't need an hour. You need enough cold to trigger the skin temperature drop that drives the neural and hormonal cascade. Two to three minutes. Consistent. Over weeks.

If you're using cold for mental health — which is where the anecdotal evidence is strongest — that's the protocol. Not heroic sessions. Not colder for longer. Consistent moderate exposure that lets your body adapt without overwhelming it.

The Surprising Connection

Tipton notes that we are, at our core, tropical animals. We're designed for 28 degrees Celsius, naked in air. Every cold exposure is a departure from baseline — a deliberate mismatch between environment and biology. That mismatch is the signal. The adaptation to that mismatch is the benefit.

When you frame it that way, contrast therapy makes immediate sense. Cold followed by heat isn't just comfort after discomfort. It's two signals, back to back, each triggering a different cascade, each reinforcing the other's adaptive response. The oscillation is the protocol. Tipton's work on cold is the first half of that story. The sauna (more on this here) research is the second. Together, they're the full picture of what deliberate thermal stress can do when applied with care and consistency.