Women, Cold Exposure & The Problem With Simple Answers
- Kym Burls
- 1 day ago
- 9 min read
When did "women respond differently to the cold" become "women shouldn't use cold exposure"?
Over the last year, I've lost count of how many conversations I've had with women questioning whether they should be using cold exposure at all.
"I heard cold plunges aren't good for women."
"Someone told me ice baths increase cortisol too much."
"I've heard they can affect your hormones."
"I'm not sure whether I should stop."
Many of these conversations can be traced back to a discussion that gained traction after exercise physiologist Dr Stacy Sims argued that women may not need near-freezing temperatures to obtain many of the benefits associated with cold exposure (Sims, 2025).
Her position, in simple terms, is that women respond differently to cold than men and may not require the same temperatures or protocols that have become popularised within many cold exposure communities (Sims, 2025).
While that’s not an unreasonable position, where I think things start to go wrong is what happened next.
Judging by the number of conversations I've had, many women have come away with the impression that cold exposure is somehow less suitable for them than it is for men.
Those are two very different ideas.
The first is a physiological observation.
The second is a recommendation.
And the evidence doesn't support treating them as though they're the same thing.
Women do respond differently to cold than men. Hormones influence that response, the menstrual cycle can shape it further, and factors such as temperature, duration and individual physiology all play a role in how cold is experienced. But none of that automatically leads to the conclusion that women should avoid cold exposure altogether.
After nearly a decade of teaching cold exposure to both men and women, I've found that understanding the differences is far more useful than being concerned by them.
Women And Men Don't Respond To Cold In The Same Way
Let's start with the part that's uncontroversial.
Women and men are physiologically different, and those differences influence how the body responds to cold.
On average, women tend to have less muscle mass, more body fat and a lower resting metabolic rate than men. Those differences alone influence heat production, heat retention and thermal comfort (Iyoho et al., 2017).
Observed differences also exist that extend beyond body composition.
Research suggests women generally exhibit greater brown adipose tissue (BAT a.k.a 'brown fat') activity than men and may recruit this tissue more readily during cold exposure. Unlike shivering, which generates heat through muscular contractions, brown fat produces heat directly. This means women may rely more heavily on non-shivering thermogenesis when exposed to cold (Rodríguez-Cuenca et al., 2012; Iyoho et al., 2017).
Women also tend to maintain a slightly higher core temperature while exhibiting lower peripheral temperatures. In practical terms, this often translates into colder hands and feet despite the body's core temperature remaining stable (Iyoho et al., 2017).
There are hormonal influences at play as well.
Oestrogen appears to support brown fat activity and thermoregulation, while progesterone has a thermogenic effect that increases core body temperature (Rodríguez-Cuenca et al., 2012).
None of these observations are particularly controversial, and the research supporting them is reasonably consistent.
The challenge begins when we try to translate physiology into recommendations.
The menstrual cycle provides perhaps the most obvious example of this.
The Menstrual Cycle Matters. Just Not In The Way You Think.
One of the most common questions I receive from women is whether they should change their cold exposure practice throughout the month.
The short answer is: maybe.
The slightly longer answer is: listen to your body.
During the follicular phase, which begins after menstruation, oestrogen gradually rises and body temperature tends to be slightly lower. Some researchers have suggested BAT activity may also be enhanced during this phase, potentially improving cold tolerance (Rodríguez-Cuenca et al., 2012).
During the luteal phase, progesterone rises and core temperature typically increases by around 0.3–0.7°C. Many women report feeling different in both hot and cold environments during this phase (Matsuda-Nakamura et al., 2015).
At first glance, the physiology appears straightforward.
Follicular phase equals better cold tolerance.
Luteal phase equals worse cold tolerance.
The problem is that human beings rarely behave as neatly as a textbook would like.
While researchers have observed measurable physiological differences across the menstrual cycle, Matsuda-Nakamura and colleagues found that changes in core temperature did not necessarily translate into meaningful differences in cold perception or autonomic cold-defence responses (Matsuda-Nakamura et al., 2015).
This is one of the reasons I'm cautious about making blanket recommendations.
The menstrual cycle clearly influences physiology. What's less clear is how consistently those physiological changes translate into real-world experience.
Some women notice substantial differences throughout the month. Others notice very little.
And that's all before we account for sleep, stress, recovery, nutrition, illness and the countless other variables that influence how we experience any physiological stressor.
What The Research Actually Shows
When people hear that women respond differently to cold, it's easy to imagine those differences must be dramatic.
They're not.
The differences are real, measurable and physiologically interesting. Women appear to use thermoregulatory strategies differently to men, including greater reliance on non-shivering thermogenesis through brown fat, different patterns of heat production, and differences in peripheral temperature regulation (Iyoho et al., 2017; Rodríguez-Cuenca et al., 2012).
Those differences help explain why two people can have very different experiences in the same water temperature. They may also help explain why some women find moderately cold water more effective, tolerable or repeatable than near-freezing exposure.
What they don't do is tell us exactly what temperature every woman should use.
That is the part of the conversation I think often gets lost. Research can identify physiological differences, but practical recommendations still need to account for temperature, duration, menstrual cycle phase, previous exposure, stress load, recovery and individual response.
Cortisol, Catecholamines And The Fear Of Stress
If there's one reason many women have become wary of cold exposure, it's probably cortisol.
At some point, cortisol stopped being viewed as a normal and necessary stress hormone and started being treated as though it were inherently harmful.
Again, the reality is more nuanced.
A stress response is not the same thing as a harmful response.
Cold exposure activates the sympathetic nervous system and stimulates the release of catecholamines such as adrenaline and noradrenaline. Cortisol can rise as part of that response.
This isn't a side effect of cold exposure. It's one of the mechanisms through which cold creates adaptation.
The same could be said for exercise. Many forms of physical adaptation involve temporary increases in stress hormones. While a demanding strength training or sprint session both elevate cortisol, the presence of cortisol alone tells us very little.
The more useful question is whether the stressor is appropriate, recoverable and adaptive, and this is where I partially agree with Dr Sims.
I think many people have been conditioned to believe that colder is always better.
It's not.
A 2°C plunge is not automatically superior to a 12°C plunge.
10 minutes is not automatically superior to three.
More stress does not automatically create more benefit.
Like most physiological interventions, cold exposure exists on a spectrum. Too little may not create much stimulus. Too much may become unnecessarily stressful.
That's true whether you're a man or a woman. In fact, it's a theme I've written about before. Rather than chasing the perfect temperature, time or technique, I think it's far more useful to build a consistent practice that suits your body, your goals and your circumstances. If you'd like to explore that idea further, you might enjoy my article The 4 T's of Cold Exposure.
The challenge is that we don't yet have enough evidence to confidently draw a universal line and declare that one temperature is appropriate for all women.
The thyroid conversation deserves similar nuance.
The thyroid plays an important role in thermoregulation and energy expenditure, which is one reason concerns occasionally emerge when cold exposure is discussed. However, the current evidence base is not sufficiently clear (for me at least) to make strong recommendations based on thyroid considerations alone.
At this stage, broad claims that cold exposure is either beneficial or harmful for thyroid function in otherwise healthy women appear to go beyond what the available evidence can confidently support.
What Years Of Teaching Cold Exposure Has Taught Me
I've guided thousands of people through cold exposure experiences, and one pattern has remained surprisingly consistent.
Women frequently arrive carrying more doubt than men. They tend to ask more questions, seek more reassurance and spend more time wondering if they'll manage once they're in the water.
Yet those initial impressions rarely predict what happens next.
Time and again, I've watched women settle into the experience amazingly well. Once the initial shock passes, most work with, and surrender to, the sensations rather than fight them. Their attention shifts towards their breathing, their body and the experience unfolding in front of them.
Men tend to arrive at the same place eventually, but often by a different route. The instinct to grit your teeth, tense up and mentally overpower the experience can sometimes become its own obstacle.
This isn't a claim that women are better at cold exposure than men. It's simply an observation that the qualities often associated with successful cold exposure—awareness, adaptability and responsiveness—don't necessarily favour the toughest person in the group.
Cold exposure is often portrayed as a test of willpower. In practice, I've found it behaves more like a conversation.
The people who seem to get the most from it are rarely those trying to dominate the experience. They're the people willing to listen to it.
Endometriosis And The Challenge Of Universal Advice
One of the challenges with conversations around women's health is that the same intervention can produce very different experiences in different people.
Endometriosis is a good example.
Depending on who you ask, cold exposure may be helpful, unhelpful or entirely neutral.
Some researchers have identified cold exposure as a potential risk factor associated with primary dysmenorrhea (menstrual pain occurring in the absence of an underlying condition), while others have proposed mechanisms through which cold exposure may influence inflammation, pain perception and immune activity (Wang et al., 2022).
In practice, I've seen similarly mixed responses. Some women report that cold exposure helps them manage symptoms. Others prefer heat. Some move between the two depending on where they are in their cycle and what symptoms they're experiencing.
During 2025, I had the opportunity to participate in a pilot research project with Adelaide University exploring the effects of breathwork, meditation and cold-water exposure in women with endometriosis.
The results were encouraging. Cold-water exposure was associated with reductions in pain symptoms and improvements in several self-reported outcomes. The intervention was also well tolerated, with no adverse events reported (Dodds et al., 2025).
At the same time, the findings should be interpreted cautiously. This was a small pilot study involving a multi-factorial intervention, and no responsible researcher would suggest the results settle the discussion.
What I found most interesting wasn't whether the study proved cold exposure works for endometriosis. It didn't.
Rather, it reinforced something I've observed repeatedly in practice: individual responses matter.
There remains considerable scope for future research to better understand who may benefit most from cold exposure, when it may be most appropriate, and what protocols are best suited to different circumstances.
Until then, the study serves as a useful reminder that responses to cold exposure are often far more individual than blanket recommendations imply.
Where Does That Leave Us?
After spending time with both the research and the real-world experiences of the women I work with, I'm not convinced this question can (or should) be answered with a single recommendation.
Most of the women who ask me whether they should continue cold plunging are looking for certainty. That's understandable. Health information is often presented as a series of rules, and rules feel reassuring.
Yet cold exposure seems to resist that kind of simplicity.
The research can help us understand why women may experience cold differently. It can help explain the role of hormones, thermoregulation and the menstrual cycle. It can provide useful context and help us ask better questions.
What it can't do is tell an individual woman exactly how she will respond.
And perhaps that's where the conversation becomes most useful.
Not in deciding whether women should or shouldn't use cold exposure, but in helping women better understand the factors that shape their own experience of it.
References
Dodds, K., Chalmers, J., Bajic, J., Woenig, J., Morphett, J., Musolino, S., Caines, M., Chi, L. Y., O’Hara, R., Deslandes, A., Burls, K., & Hutchinson, M. (2025). The EndoChill Trial: Evaluating meditation, breathwork & cold-water exposure as a multimodal intervention for endometriosis-associated pain.
Iyoho, A. E., Ng, L. J., & MacFadden, L. N. (2017). Modeling of Gender Differences in Thermoregulation.
Matsuda-Nakamura, M., Yasuhara, S., & Nagashima, K. (2015). Effect of menstrual cycle on thermal perception and autonomic thermoregulatory responses during mild cold exposure.
Rodríguez-Cuenca, S., Monjo, M., Frontera, M., Gianotti, M., Proenza, A., & Roca, P. (2012). Role of sex hormones in modulation of brown adipose tissue activity.
Sims, S. (2025). Cold Plunging for Women: Why Colder Isn't Always Better.
Wang, L. et al. (2022). Prevalence and Risk Factors of Primary Dysmenorrhea in Students: A Meta-Analysis.
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