Do Sex Hormones Modify Women's Cold Sensitivity?
- Thomas P Seager, PhD
- 3 days ago
- 9 min read
Updated: 3 days ago
Summary
The differences between men and women with regard to cold sensitivity are unlikely to be the consequence of innate biological differences, despite popular misconceptions to the contrary.
Post-menopausal women report relief from symptoms resulting from a regular practice of winter swimming.
Hormonal changes during menstruation do not impact cold sensitivity.
Women who are menstruating normally, without hormonal birth control, respond faster to cold training than men, and faster than women who do take oral contraceptives.
Are Women More Sensitive to Cold Than Men?
In my article Ice Bath Benefits Women, I was critical of sensational social media posts citing Stacy Sims PhD as saying "Ice baths are bad for woman." There are several problems with them:
Sims makes a serious logical error in thinking that what is true for a population in general also applies to an individual. Although male and female bodies are different (and no one should have to remind their readers of this), in matters of cold sensitivity the specific differences between individuals of the same sex are much more significant than the average differences between the sexes.
The exaggerated and oversimplified headlines misrepresent what Sims actually said, and overlooked the benefits that Sims herself also described.
Sims leaves the impression that research comparing male and female differences in sensitivity to cold is somehow due to innate physiological differences between the sexes, instead of differences in the extent to which men and women have prior experience with cold exposure.
Nevertheless, Mel Robbins recently boasted that her interview with Sims "became the #1 most shared episode of 2025 of every podcast in the world."
It doesn't matter that it's wrong.
Sims cites only two studies in her article as the scientific basis for her conclusions. One of those studies is careful to point out that they measured no differences between men and women when monitoring fingertips during cold stimulation, and that "all previous studies on the topic reported no effects of sex on cold-induced vasodilation (CIVD) in the fingers." The authors in that study explain that to detect any difference at all, they had to immerse one foot of their research subjects in cold water and instrument three toes on the other foot that was kept warm and dry (Tsoutsoubi et al. 2022). Otherwise, responses between the sexes are indistinguishable.
The other study Sims cites wasn't in an ice bath at all -- instead, Dutch researchers used a chilled-water vest, gradually reducing the temperate of the water over time and noting when the subjects started shivering, if at all. When Sims is explaining to Robbins how men and women react to the "shock" of the ice bath, it doesn't call to mind a gradual chill in a cooling vest. Moreover, both women and men were placed in exactly the same vest. Sure enough, Dutch women shivered at warmer temperatures, and reported feeling less comfortable at colder temperatures than Dutch men.
A Lithuanian study in which men and women were placed in a cool bath (14°C or 57°F) did show some differences between men and women, but not in the rate at which their bodies cooled. In the Lithuanian study, men showed greater metabolic heat production response while women showed greater insulative (e.g., vasoconstriction) response. Neuroendocrine changes were more pronounced in the men than the women (Soliniak et al 2014).
All of which might make you wonder why Sims would make the rounds of the biggest podcasts in the world, just to say things that are not substantiated by the data. I think it's because the only thing that matter in the world of wellness influencers is what gets clicks, and in Sims' case her popular appearances on podcasts hosted by Andrew Huberman, Steven Bartlett, Mel Robbins, and others were telling her audience what they wanted to hear. Nevertheless...
The most important thing about individual cold sensitivity is the extent to which that individual has already been cold trained.
This should be obvious to most people, if only by analogy to exercise. For example, if you search online for advice on starting a weight training program, Google and other AI agents will correctly tell you that the weight and number of reps that is right for you depends on your prior state of weight training. Stronger people will benefit from heavier weights and more reps than people who have never lifted weights before. By contrast, when you search online for advice about starting a cold plunge therapy program, somehow Google claims that there's one best temperature and one best time duration that applies to everyone.
It's a serious and persistent misconception.
One of the peculiar things about Sims' career as an an author and influencer is that she has registered the phrase "Women are not small men" as her trademark. She now owns that combination of words, as if it were some unique insight that she discovered for herself.
Despite that, much of Sims book emphasizes the exercise physiology similarities between men and women. "When you training into the equation, the sex-difference gap shrinks considerably," she writes (ibid, p14).
Where Sims and I seem to disagree is that she thinks training only applies to exercise and I think it also applies to cold.
Sex Hormones and Cold Sensitivity
Neither Sims nor I have written much about the actual differences between men and women that are relevant to cold sensitivity. In her book Roar she makes clear that the principal difference in physiology that relates to exercise performance are the hormones (Sims 2024, p9).
Hormones complicate study of women, at least compared to men, in two ways. The first is that changes in sex hormones occur over the course of a woman's menstrual cycle that are much greater than those that occur in men. The second is that many menstruating women take hormonal birth control, and men do not.
To study the effect of hormone status on cold sensitivity, it's helpful to create at least three groups (not two): 1) naturally menstruating women, 2) women taking hormonal birth control, and 3) men.
Certainly a fourth group worth of study are menopausal women, who no longer ovulate and consequently are no longer subject to the same hormonal fluctuations as their younger counterparts. In fact, in a recent survey of more than a thousand menopausal and perimenopausal women who practice winter swimming in the United Kingdom, researchers found that women who swam reported that the practice "reduced their menstrual symptoms, notably psychological symptoms such as anxiety (46.7%), mood swings (37.7%) and irritability (37.6%). Perimenopausal women reported a significant improvement in anxiety (46.9%), mood swings (34.5%), low mood (31.1%) and hot flushes (30.3%)" (Pound et al. 2024b). Moreover, the majority of women with symptoms said their winter swimming was specifically motivated to reduce these symptoms, that they felt it was the cold water that helped their symptoms, and that cold temperatures were more effective. (See also Pound et al. 2024a). However, the survey did not include or compare outcomes to men.
Fortunately, an older study published in The Journal of Pain compared the cold sensitivity of men, normally menstruating women, and women taking hormonal birth control, to cold using the cold pressor test (4°C/40°F). Researchers at Columbia University spread ten sessions of cold exposure out to capture all different stages of the menstrual cycle. The participants repeated the cold pressor test at each sessions, while the scientists tracked self-reported pain thresholds (the moment it starts hurting) and tolerance (how long until they couldn't stand). What did they find?
Pain tolerance was similar across all groups, and neither threshold nor tolerance shifted meaningfully with the ebb and flow of the menstrual cycle. Normally menstruating women did show a slightly higher pain threshold overall compared to men, who scored slightly higher than the women taking hormonal birth control, but the most interesting finding emerged when the researchers examined adaptation across repeated exposures -- i.e., the effects of training.
Men showed a slow, steady increase in tolerance. Women on oral contraceptives showed no improvement.
Normally menstruating women adapted the fastest to cold training using the cold pressor test. Their pain threshold climbed steadily, and tolerance shot up during their first four sessions (Kowalczyk et al. 2006) -- a finding corroborated a year later by researchers doing a similar study in Sweden (Stening et al. 2007).
More recent research supports the initial reports from two decades ago. When researchers in Iowa used the cold pressor test to compared cold tolerance between groups of men, women not using oral contraception (NC), and women who were using oral contraception (OC) they again found few differences between the men and women as a whole (Bock et al. 2025). However, the difference between the women taking oral contraceptives and those who did not were more significant. They wrote that "Within the females who were taking an oral contraceptive, lower blood pressure and heart rate responses to a CPT (cold pressor test) were observed relative to females not using an oral contraceptive."
These findings shatter Sims stereotype of sex differences in cold sensitivity, but they also challenge my intuitions about cold training. Although I still think that the prior state of cold training is the single most important factor in determining sensitivity to cold, I must now revise my beliefs to include the fact that hormone status modifies response to cold training.
These patterns suggest that normally menstruating women adapt to repeated cold pressor pain differently than men and women on oral contraceptives. The rising pain threshold and tolerance over sessions in normally menstruating women may reflect a hormonal influence on pain adaptation and cold sensitivity that has yet to be captured in any clinical study that fails to control for hormonal birth control. Moreover, it is incorrect to make broad generalizations that expect the same cold sensitivity from women taking oral contraceptives as might be expected from those who are not.
Practical Takeaways for Menstruating Women
While the UK survey data and the experiences of menopausal women using cold plunge therapy to maintain healthy sex hormone levels suggest that cold is a tremendous boon for women post-menopause, it's still uncertain whether there are times during the menstrual cycle when it might be advisable for younger women to refrain from the ice bath.
Wim Hof-certified Instructor Josephine Worseck, PhD, told me that when she was seeking to conceive, she stopped doing ice baths right around the time she was ovulating. She reasoned that she didn't want to boost her immune system at the very moment the zygote (fertilized egg) might be seeking to implant in the uterine lining of her womb. Later in her pregnancy, she resumed her ice bath practice.
That seems like sound advice to me. There is nothing about taking a few days off just before, during, and after expected ovulation that will cause a woman's metabolism or fertility to lapse into dysfunction.
Nevertheless, that's not what this study shows. There are only two conclusions we might draw from the Columbia University data:
Hormonal fluctuations during the menstrual cycle do not predict changes in cold sensitivity.
Normally menstruating women may develop greater cold tolerance by repeating exposures faster than men and women on oral contraceptives.
Women taking birth control pills can not make reliable inferences ab out cold sensitivity based on studies (or podcasts) that do not control for hormonal contraception status.
References
Bock JM, Hanson BE, Miller KA, Casey DP. The associations between cardiovascular and pain responses to a cold pressor test differ between males and females. European Journal of Applied Physiology. 2025 Jan 16:1-0.
Kaikaew K, van den Beukel JC, Neggers SJ, Themmen AP, Visser JA, Grefhorst A. Sex difference in cold perception and shivering onset upon gradual cold exposure. Journal of thermal biology. 2018 Oct 1;77:137-44.
Kowalczyk WJ, Evans SM, Bisaga AM, Sullivan MA, Comer SD. Sex differences and hormonal influences on response to cold pressor pain in humans. The Journal of Pain. 2006 Mar 1;7(3):151-60.
Pound M, Massey H, Roseneil S, Williamson R, Harper M, Tipton M, Shawe J, Felton M, Harper J. The swimming habits of women who cold water swim. Women's Health. 2024a Aug;20:17455057241265080.
Pound M, Massey H, Roseneil S, Williamson R, Harper CM, Tipton M, Shawe J, Felton M, Harper JC. How do women feel cold water swimming affects their menstrual and perimenopausal symptoms?. Post reproductive health. 2024b Mar;30(1):11-27.
Sims ST. ROAR, Revised Edition: Match Your Food and Fitness to Your Unique Female Physiology for Optimum Performance, Great Health, and a Strong Body for Life. Rodale Books; 2024 Jan 9.
Solianik R, Skurvydas A, Vitkauskienė A, Brazaitis M. Gender-specific cold responses induce a similar body-cooling rate but different neuroendocrine and immune responses. Cryobiology. 2014 Aug 1;69(1):26-33.
Stening K, Eriksson O, Wahren L, Berg G, Hammar M, Blomqvist A. Pain sensations to the cold pressor test in normally menstruating women: comparison with men and relation to menstrual phase and serum sex steroid levels. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 2007 Oct;293(4):R1711-6.
Tsoutsoubi L, Ioannou LG, Mantzios K, Ziaka S, Nybo L, Flouris AD. Cardiovascular stress and characteristics of cold-induced vasodilation in women and men during cold-water immersion: a randomized control study. Biology. 2022 Jul 13;11(7):1054.
About the Author
Thomas P Seager, PhD is an Associate Professor in the School of Sustainable Engineering at Arizona State University. Seager co-founded the Morozko Forge ice bath company and is an expert in the use of ice baths for building metabolic and psychological resilience.
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