Testosterone does increase the amount of heat your body produces, primarily by raising your metabolic rate and building more metabolically active tissue. But “producing more heat” and “feeling warmer” are not the same thing, and the full picture involves some genuine surprises. The hormone simultaneously dials up one heat source while dialing down another, and its effects on blood flow, sweating, and even your brain’s thermostat add layers that make a simple yes-or-no answer misleading.
More Muscle, More Heat
The most straightforward way testosterone affects body temperature is through metabolism. In a study of normal men and men with muscular dystrophy, three months of testosterone treatment raised basal metabolic rate by an average of about 10%, with lean body mass climbing by roughly the same proportion. The researchers concluded that the metabolic boost was largely explained by the extra lean tissue, which burns more energy at rest than fat does.1PubMed. Effect of testosterone on metabolic rate and body composition in normal men and men with muscular dystrophy A higher metabolic rate means more chemical reactions happening in your cells, and more chemical reactions means more waste heat. In that basic thermodynamic sense, testosterone does make you warmer.
Animal research has drilled into the mechanism a step further. In male mice given testosterone, heat production went up, and the increase was traced to greater mitochondrial activity specifically in skeletal muscle. The muscle cells ramped up production of the molecular machinery needed to burn fuel, while other tissues like the liver and brown fat did not show the same boost. Mice that lacked functional androgen receptors showed the opposite pattern: their muscle mitochondrial genes were turned down.2FEBS Letters. Elevated mitochondrial biogenesis in skeletal muscle is associated with testosterone-induced body weight loss in male mice So the extra heat is coming from your muscles, not from some generalized warming of every tissue.
The Brown Fat Trade-Off
Here is where things get counterintuitive. Brown adipose tissue, the specialized fat that generates heat to keep you warm in the cold, actually becomes less active in the presence of testosterone. In male mice, castration caused a dramatic increase in brown fat metabolic activity, with fatty acid uptake jumping roughly four and a half times compared to intact males. Giving testosterone back to castrated mice reversed that surge, bringing brown fat activity back down.3Journal of Endocrinology. Testosterone reduces metabolic brown fat activity in male mice
Cell-culture work tells a consistent story. Brown fat cells treated with testosterone developed fewer and smaller fat droplets, and the expression of UCP1, the key protein that allows brown fat to convert energy directly into heat, dropped in a dose-dependent way. Blocking the androgen receptor with an antagonist reversed the suppression, confirming that testosterone was acting through its usual receptor pathway.4PubMed Central. Opposite actions of testosterone and progesterone on UCP1 mRNA expression in cultured brown adipocytes Separately, mice engineered to lack androgen receptors showed greater UCP1 induction in brown fat when given a drug that activates it, further confirming that androgen signaling puts a brake on this tissue’s heat-generating capacity.5Journal of Biological Chemistry. Androgen receptor signaling suppresses brown adipose tissue thermogenesis and enhances metabolic heat production
So testosterone reshuffles where your heat comes from rather than simply turning up a master thermostat. It suppresses brown fat thermogenesis while boosting heat production from skeletal muscle. The net result may be roughly similar total heat output, but the source of that heat shifts. This distinction matters because brown fat activation is especially important in cold environments, which may partly explain why the relationship between testosterone and feeling warm is not as clean as people expect.
Blood Flow to the Skin
Whether you feel warm or cold depends heavily on what is happening at your skin surface. Blood vessels in the skin open and close to regulate heat loss, and sex hormones influence this process, though not always in the direction you might guess. A study comparing men, premenopausal women, postmenopausal women, and women on oral contraceptives found that males showed a less pronounced and less prolonged vasoconstriction response to cold. In practical terms, men’s skin blood flow stayed higher during and after cooling, which would make their fingers and extremities feel warmer in the cold.6PubMed. Skin vascular reactivity in healthy subjects: influence of hormonal status
But when researchers directly tested whether giving testosterone to older men changed their skin’s vasodilator response to local warming, the answer was essentially no. Testosterone treatment did not consistently alter how much the skin blood vessels opened up in response to heat, and neither did estradiol at the doses used.7PubMed. Effects of testosterone and estradiol on cutaneous vasodilation during local warming in older men The sex differences in skin blood flow that do exist may reflect years of developmental and compositional differences between male and female bodies rather than any acute effect of circulating testosterone levels.
In women with polycystic ovary syndrome (PCOS), who have elevated androgen levels, the picture is different again. Suppressing androgens with a GnRH antagonist improved microvascular dilation during local skin heating, and adding testosterone back partially reversed that improvement. The effect worked through endothelin receptors, which are involved in blood vessel constriction.8PubMed Central. Androgens influence microvascular dilation in PCOS through ET-A and ET-B receptors This suggests that chronically elevated androgens in women may actually impair the skin’s ability to dump heat efficiently, a context-dependent effect that would not apply to men with normal testosterone ranges.
What Happens When Testosterone Disappears
Some of the strongest evidence for testosterone’s role in temperature regulation comes from observing what happens when the hormone is taken away. Men with prostate cancer who undergo androgen deprivation therapy frequently develop hot flashes, often described as sudden waves of intense heat and flushing. These vasomotor symptoms are among the most common side effects of the treatment, alongside loss of muscle mass, bone density changes, and altered body composition.9PubMed Central. Androgen deprivation therapy-associated vasomotor symptoms The experience closely mirrors what many women go through during menopause, when estrogen drops sharply. In both cases, the brain’s thermoregulatory center appears to narrow the range of temperatures it considers “normal,” triggering heat-dissipation responses like flushing and sweating even when core temperature hasn’t meaningfully changed.
Working from the other direction, an internet-based pilot study of perimenopausal and postmenopausal women using testosterone replacement therapy found that participants reported improvements in hot flashes and night sweats, along with better sleep and reduced vaginal dryness.10PubMed. Perceived effects of testosterone replacement therapy in perimenopausal and postmenopausal women: an internet pilot study A more recent study of testosterone therapy in menopausal women found significant improvements across a broad range of symptoms, with particularly large reductions in sexual problems, anxiety, and physical exhaustion.11PubMed Central. The benefits of testosterone therapy for menopausal symptoms This is worth noting because hot flashes are a vasomotor symptom, not strictly a temperature-regulation problem. The hormone’s disappearance destabilizes the thermostat, not the furnace.
Sweating and Exercise in the Heat
If testosterone increases metabolic heat production, you might expect it to affect how your body cools itself during exercise. Research on women with PCOS suggests androgens do influence sweating. In one study, obese women with PCOS started sweating at a lower core temperature than controls when sex hormones were suppressed, and their peak sweating rate was roughly double that of the control group. When both estrogen and testosterone were added back, the elevated sweating in the control group was attenuated, but the PCOS group maintained a higher sweating rate.12PubMed Central. Greater Exercise Sweating in Obese Women with Polycystic Ovary Syndrome Compared with Obese Controls The chronic androgen excess in PCOS appears to reset the sweating response, making these women more aggressive heat-dumpers, which you could interpret as their bodies compensating for the extra metabolic heat that comes with higher testosterone.
In mice, castration had a surprising effect on heat tolerance during forced exercise. Castrated mice actually reached a core temperature of 39.5°C faster during exertional heat stress, despite having about 10% lower body mass. Yet they ran similar distances and hit similar peak core temperatures before collapsing.13PLOS ONE. The impact of castration on physiological responses to exertional heat stroke in mice The lack of testosterone did not protect them from heat stroke or give them any performance advantage. If anything, the faster temperature rise suggests that without testosterone’s influence on muscle mass and metabolism, the smaller animals had a less favorable heat-to-mass ratio during intense exertion.
Does Testosterone Actually Change How Warm You Feel?
This is arguably the question most people are really asking, and the evidence here is surprisingly thin. A recent study tracked transgender men starting testosterone therapy, along with cisgender male and female controls, and measured their ability to detect warm and cold stimuli on the skin at multiple time points. The result: no changes in cold or warm temperature detection thresholds in any group over the study period.14PubMed Central. Changes in temperature perception in transgender persons undergoing gender-affirming hormone therapy Testosterone did not make the skin more or less sensitive to temperature. Whatever subjective sense of being “warmer” people report on testosterone, it does not appear to come from a change in the nerve endings that detect heat and cold.
A Japanese study of men and postmenopausal women aged 50 and older reached a similar conclusion from a different angle. After measuring blood levels of testosterone, estradiol, and several other hormones, the researchers found that sensitivity to cold was not associated with circulating hormone concentrations in either sex.15Gender Medicine. Differences in Sensitivity to Cold in Japanese Men and Postmenopausal Women Aged ≥50 Years People with higher testosterone were not less bothered by cold, and people with lower testosterone were not more bothered by it. The disconnect between measurable hormone levels and subjective thermal comfort suggests that other factors, including body size, fat distribution, cardiovascular fitness, and habitual cold exposure, matter far more for whether you walk around feeling warm or chilly.
In a human study that directly measured supraclavicular temperature (a rough proxy for brown fat activity), baseline skin temperature above the collarbone did not correlate with testosterone concentrations.16European Journal of Endocrinology. Effect of sex and sex steroids on brown adipose tissue heat production in humans Estradiol showed a weak positive correlation with cold-induced thermogenesis, but testosterone showed none. So even at the tissue level where you would most expect to see a hormone-heat link, testosterone is not clearly pulling the temperature up.
Why Sex Differences in Temperature Preference May Not Be About Current Hormones
There is a well-known sex difference in thermal preference: women tend to prefer warmer environments than men. It is tempting to attribute this to testosterone, but a mouse study designed to test exactly that question found something unexpected. Female mice preferred ambient temperatures about 0.9°C higher than male mice, a real and statistically significant difference. But when the researchers removed the gonads from both sexes, eliminating the main source of sex hormones, the preference gap persisted. Gonadectomy did not shift temperature preference in either males or females.17Comprehensive Physiology. Reproductive Hormone Influences on Thermoregulation in Women Whatever drives the sex difference in how warm an environment feels comfortable, it is not simply a matter of circulating testosterone or estrogen levels in adulthood.
Rat research points to a possible explanation. A neonatal surge of testosterone that occurs shortly after birth in male rats appears to permanently organize the circadian rhythm of core body temperature. Males castrated at birth showed a significantly earlier rise in core temperature during the light phase compared to intact males. Giving testosterone back in adulthood did not fix the disruption. But a single injection of testosterone at birth, mimicking the natural neonatal surge, followed by adult testosterone replacement, fully normalized the circadian rhythm.18PubMed Central. Organizational influence of the postnatal testosterone surge on the circadian rhythm of core body temperature of adult male rats This suggests that some of testosterone’s most important effects on thermoregulation happen during development, wiring the brain’s thermostat in ways that cannot be reversed or replicated by simply changing adult hormone levels.
The Brain’s Thermostat and Reproductive Hormones
The preoptic area of the brain is the master controller of body temperature. It contains neurons that speed up their firing when the temperature rises (warm-sensitive neurons) and others that respond to cooling. It also contains neurons that respond to reproductive hormones. The overlap between these two populations is real but partial. In rat brain slices, testosterone or estradiol affected about half of the thermosensitive neurons and about a third of the temperature-insensitive ones. There was a notable specificity, however: testosterone and estradiol rarely affected the same individual neuron.19PubMed. Effects of testosterone, estradiol, and temperature on neurons in preoptic tissue slices
This finding is significant because it tells us that reproductive hormones and temperature regulation share neural real estate, but they are not running through the same wiring in a simple one-to-one fashion. The cross-talk between the two systems helps explain phenomena like hot flashes during hormone withdrawal, where the thermostat becomes unstable, without requiring that testosterone directly “heats” the brain. The interaction is more like two different departments sharing an office building: they bump into each other in the hallway, and when one department shuts down, the other gets disrupted, but they are doing genuinely different jobs.
Testosterone During Calorie Restriction
One situation where gonadal hormones clearly influence core body temperature is during calorie restriction, when the body is trying to conserve energy. In mice, gonadal hormones contributed to sex-specific regulation of core temperature when food was scarce. Dihydrotestosterone, a potent androgen, had only minor and transient effects on preventing the drop in core temperature that comes with calorie restriction in castrated male mice.20PubMed Central. Gonadal hormones influence core body temperature during calorie restriction In other words, testosterone alone was not enough to keep body temperature up when energy intake was low. The body prioritized conserving energy over maintaining warmth, regardless of androgen status. For anyone who has noticed feeling colder on a severe diet, this research suggests the effect has more to do with energy balance than with any particular hormone level.
Why Anecdotal Reports of Feeling Warmer on Testosterone May Be Real but Indirect
If you have heard from someone starting testosterone therapy, whether for hypogonadism or as part of gender-affirming care, that they feel warmer, those reports are not necessarily wrong. They are just likely reflecting indirect effects rather than a direct temperature increase. Testosterone builds muscle, which generates more resting heat. It changes fat distribution, pulling fat away from under the skin and toward the abdomen, which could alter how heat dissipates from the body’s surface. It increases red blood cell production, which can improve oxygen delivery and potentially affect skin perfusion. And it modestly raises metabolic rate, which means more baseline heat production. All of these changes could shift someone’s subjective experience of temperature without changing how their skin’s nerve endings detect warmth, which is consistent with the finding that thermal detection thresholds do not change on testosterone therapy.
Males also tend to have less cold-induced vasoconstriction than females, meaning their extremities stay warmer in cold environments. But as the mouse gonadectomy research suggests, this may be a developmental trait baked in during early life rather than something actively maintained by current testosterone levels. A man who loses testosterone in adulthood does not suddenly develop cold hands the way a woman with naturally lower testosterone might experience them. The plumbing was laid down long ago.
The hot flash phenomenon during androgen deprivation therapy is worth keeping in mind as a cautionary tale about assuming simple relationships between hormones and temperature. The men experiencing hot flashes are not “too cold” because they lost testosterone. They are experiencing thermoregulatory instability because their brain’s thermostat lost a stabilizing signal. The problem is not too little heat. It is a control system gone haywire. Estrogen plays a similar stabilizing role in women, which is why both sexes get hot flashes when their primary sex hormone drops sharply. The hormone is not the heat; it is part of the system that keeps the body from overreacting to tiny temperature fluctuations.