Put a woman and a man in the same room at the same temperature, and the woman’s hands, feet and ears will be colder. Not because she’s imagining it. Because her body is measurably colder at the surface, and has organised itself that way on purpose.
The short answer to the question the ice-bath industry keeps dancing around: yes, women and men respond to cold differently. Women run colder at the skin, get cold faster in the water, lean harder on a tissue called brown fat to heat themselves, and take longer to warm back up. What they don’t get is a different result. The metabolic payoff at the end is the same.
Dr Susanna Søberg, PhD, founder of the Soeberg Institute, has the studies for all of it. “Just in general, women also have a colder skin temperature,” she says. “In this room, for example, just room temperature, we will have colder ears, hands and feet. This is shown also in science studies.” It sounds like folklore until a metabolic scientist starts attaching numbers to it.
Why do women get cold faster than men?
Start with what the body has to work with. Two tissues do the heavy lifting when you’re cold: muscle, and brown fat, the metabolically active tissue Søberg calls “your first responder to any cold exposure.”
Women carry less muscle. So the defence shifts. They rely more on brown fat, and more on white fat, of which women have proportionally more than men. Men have more blood vessels threaded through their muscle, more warm plumbing. Women compensate by clamping down harder at the surface. “Women will contract their blood vessels more than men,” Søberg says, “and have a colder skin temperature.”
Then there’s the pump. “We have smaller hearts too,” she says, “which means that we need to pump faster to keep our temperature up.” A smaller engine, working harder, against a body shedding heat from the surface more readily. A woman cools faster in cold water and can’t stay in as long. Climbing out, she takes longer to come back up to temperature.
None of this is a weakness. Women are solving the same problem by a different route, and the tolerance builds either way. “Women can build up a tolerance just like men do,” Søberg says. “But we do it differently.”
Do women get the same benefits from cold water immersion as men?
Here is where Søberg declines to do the thing everyone expects her to.
The expected response, the one the supplement and plunge-tub market is already making, is to take “women are different” and turn it into “women need a different protocol,” ideally one with a price on it. She won’t, because her own data won’t let her.
The differences are in the machinery: the tissues, the vessels, the heart rate doing the work. The result is a separate question, and on the result her data is blunt. “When you look at the energy expenditure during the same period of time in cold water,” she says, “it is the same in men and women. They just activate their metabolism in different ways and protect their core temperature in different ways. But the outcome is the same.”
So a woman defends her core temperature through brown fat and white fat and hard vessel constriction, a man does it through muscle mass and vascularisation, and after the same spell in the water both have spent the same metabolic currency.
She’s just as wary of the broader fashion for difference. “I don’t think that we should just state there is a difference,” she says, “just because genders are different.” The differences are real where they’re real. They don’t need inflating into a marketing category.
Why women’s cold exposure science is still thin
There’s a reason the female side of this is so under-researched, and Søberg is honest about it in a way that points back at her own work.
“What has happened until now, and actually during my PhD,” she says, “is that we are exploring men, because of a woman’s cycle.” A menstrual cycle moves body temperature around across the month. For a study measuring temperature, that variation is noise you have to control for, and controlling for it means recruiting far more women, splitting them by cycle phase, sorting who has brown fat and who doesn’t. It gets expensive fast. “In my study, we said, well, we only look at men, because that’s what we usually did.”
She doesn’t dress it up. “This has changed now,” she says, “and I think it’s a good thing.” The consequence still stands, though. How a woman in perimenopause responds, or a woman storing fat differently, or a woman on a particular hormone profile, mostly has no answer yet, because for most of this field’s short life nobody was paying to ask the question about anyone but men.
So the honest map of cold water and the female body has a big blank on it. We know women run colder at the surface, lean on brown fat, cool quickly and warm slowly. We know the payoff is the same. Past that, the page is mostly empty.
Cold water immersion for women: common questions
Do women respond to cold differently than men?
Yes. According to cold-exposure scientist Dr Susanna Søberg, women run colder at the skin, get cold faster in the water and take longer to rewarm. They rely more on brown fat and white fat to generate heat, where men draw more on muscle. The metabolic benefit, though, is the same for both.
Why do women get cold faster than men?
Women carry less muscle mass and have smaller hearts that pump faster to hold temperature, and they constrict surface blood vessels more, which leaves them with colder skin. Together this means a woman cools faster in cold water and can’t stay submerged as long as a man.
Do women get the same benefits from cold water immersion as men?
For metabolism, yes. Søberg’s research found that energy expenditure over the same time in cold water is the same in men and women. The body reaches the result by different routes, but the payoff is equal.
Is there enough research on women and cold exposure?
Not yet. Much early cold-exposure science studied men only, because the menstrual cycle’s effect on body temperature made mixed-sex studies far larger and more expensive to run. Researchers including Søberg have flagged the gap, and the field is only now starting to close it.
Dr Susanna Søberg is the founder of the Soeberg Institute and the author of Winter Swimming: The Nordic Way Towards a Healthier and Happier Life. Read our full conversation with her on cold water, hype and what actually works.
Photography Diana Light
