Ice Bath & Women — Debunking the “Ice baths are bad -rule”

Where does this misinterpretation come from — that “ice baths are bad for women,” or that “women shouldn’t go as cold,” or that “cold is only effective for women around 15 °C and not below”?

I’ll explain why that’s a total myth.
And in the next blog, I’ll show you why ice baths are actually especially powerful for women.

The origin of the myth

The so-called “15 °C rule for women” — or the claim that women shouldn’t go colder — does not come from any study that tested women in ice baths.

This misconception is a mash-up of unrelated studies that:

• didn’t test cold-water immersion at all,

• were based on mild, prolonged cooling,

• or generic advice that was not sex-specific in the first place.

It’s a patchwork of sports-recovery guidelines, open-water safety notes, and brown-fat studies — none of which were about ice baths, or advice designed for women.

Over time, this vague advice — “women don’t need to go as cold” — has been repeated online so often that it started sounding like fact.
But it’s not based on evidence.

So…………………

Where the studies actually come from?

1️⃣ Study 1:
A 2018 Journal of Thermal Biology paper cooled people under water-circulating blankets, not in cold water.
It measured when participants started shivering — women at 11.3 ± 1.8 °C, men at 9.6 ± 1.8 °C.
That’s only a ~1.7 °C difference of the average male and female (43 in total)— and it has nothing to do with immersion, health outcomes, or safety.
Yet this is the study people often cite to say “women shouldn’t go too cold” — which it never said.

(Interestingly, shivering often starts after cooling ends — not during — which this study didn’t measure, but it would be interesting to know.)

2️⃣ Study 2:
A 2015 Physiology & Behavior  paper used a 20 °C metal plate pressed on the skin for 10 seconds.
It showed women rated that local cold as stronger.
But again — this has nothing to do with cold-water immersion, safety, or benefits.

So the claim that “women shouldn’t go that cold” is based on wrong conclusions from non-immersion lab setups. So then the question still rises….

Where the 15 °C number comes from?

It actually comes from generic guidance, not women-specific science:

• Brown fat studies often keep participants just above shivering (~15–16 °C) to study BAT activation — not to set limits for ice baths or for women. (Nature)

• Sports recovery guidelines often recommend 10–15 °C as a starting point for any beginner — not a female restriction. (Cleveland Clinic)

• Open-water safety guides note that most people experience the cold-shock response below ~15 °C — that’s a general safety note, not a “no benefit below 15 °C” rule. (University of Portsmouth)

In short: the 15 °C rule is just a hand-me-down heuristic — a rough guideline, not evidence.
It’s not sex-specific, and it doesn’t mean women get no benefit below that temperature.

What the real-world evidence shows

When you look at actual outcomes in women who regularly do cold-water immersion, the data tell a different story.
Large observational studies show that colder and longer swims are linked to greater benefits — especially for anxiety, mood, and hot flushes. (PMC)

Over time, both men and women adapt:

• The shivering threshold drops (they tolerate more cold).

• Brown-fat activation increases (more heat without shivering).

• Skin blood flow and nerve sensitivity adjust.

• Comfort improves — cold feels less cold.

• The cardiovascular system becomes more resilient and better regulated.

• Glucose uptake in intercostal muscles improves, enhancing metabolic flexibility.

The bottom line

The “15 °C for women” rule is not a scientific finding.
It’s a misinterpretation of unrelated studies and generic temperature protocols — repackaged as a rule.

Why Ice Baths Are Especially Powerful for Women

A stronger stress response isn’t a reason to avoid an ice bath.
It’s exactly the reason why we should do them.

Because the mental and physiological stress response can be trained — and the most effective way to train it is through brief, controlled, cold exposure.

Longer, mild cold doesn’t create the same adaptation as a short, sharp hormetic stressor — like a 2–3 minute ice bath.

An ice bath is not punishment. Its power lies not in avoiding stress, but in transforming it — and our response to it.

Millions of women practice the wim hof method, including cold water immersion, let’s not shut down their voice … or suppress their opportunity to gain all these amazing benefits. 

They deserve them equally as men.

In the next blog, we’ll explore why ice baths — when practiced consciously and progressively — can be extremely beneficial for women.