Is it good to wear socks to bed: Brehan Crawford, L.Ac., explaining how cold feet affect immune system activity

Is It Good to Wear Socks to Bed?

Table of Contents

    Share

    A reel from @jelloskinbyava asked a simple question: who wears socks to bed? She has worn them every night of her life, even in the dead of summer, because she grew up learning that your feet are tied to your overall health, especially if you are a woman. As a Chinese medicine practitioner, I agree with her. Here is why your feet matter so much, what cold does once it gets in, and how to keep them warm at night.

    The short answer

    Not everybody has to wear socks to bed every night, but you must keep your feet warm at all times. Cold and damp absolutely do enter your body through the feet. If your feet are cold at night, warm them with a foot soak and bundle them up in nice thick socks before you go to bed. When your feet are cold, your blood vessels constrict, less of your immune activity reaches your toes, and over time that is how cold toes can lead to foot fungus.

    The short version, on video.

    Is it good to wear socks to bed?

    Yes, if your feet are cold. Not everybody has to wear socks to bed every night, but it is true that you must keep your feet warm at all times. Socks are simply the easiest way to do that through the night.

    The reel puts it well: feet are not just feet. They are entry points. They are gateways. That is how Chinese medicine has always seen them.

    Sleep research has started to measure what that habit does. In Korea, where bed socks are a common winter habit, researchers had young men sleep for seven hours in a cool room with and without feet-warming bed socks. With socks on, they fell asleep 7.5 minutes faster, slept 32 minutes longer, woke 7.5 fewer times, and their sleep efficiency was 7.6 percent higher. Their feet stayed about 1.3°C warmer all night.[1]

    There is a reason warm feet bring sleep. In a Basel sleep laboratory, the warmth of the hands and feet compared with the trunk was the best predictor of how quickly people fell asleep, better than core body temperature, heart rate, melatonin or how sleepy they felt.[2] Habits like this, small and done every day, are the kind of thing we work on together inside Gut Brain Synchrony.

    Why should you keep your feet warm in Chinese medicine?

    Because in traditional Chinese medicine, cold enters your body from the bottom up. Cold and damp absolutely do enter your body through the feet.

    Damp and cold are received from below

    The Suwen, the oldest classic of Chinese medicine, says that wind attacks the upper body first and damp attacks the lower body first. Cold behaves the same way. The feet rest on the floor, they are the part of you farthest from the heart, and they are the first part of you to meet a cold tile, a wet bathroom or a winter night.

    Six channels start or end in the feet

    Six of the twelve main channels begin or end on the feet. The three yin channels of the foot, Spleen, Liver and Kidney, all start there and climb the inner leg into the lower abdomen. The Kidney channel begins at Yongquan, KI1, "Gushing Spring," on the sole itself, the only main channel that starts where your foot meets the floor. When cold gets in at the feet, it has a road straight up.

    Cold contracts, warmth moves

    The Suwen describes cold entering the channels, slowing the flow and making the blood congeal so it no longer moves freely. Cold contracts. Warmth moves.

    This is the everyday habit behind the advice. In China, you don't go barefoot in the shower. You don't go barefoot on cold, hard floors. And if your feet are cold at night, you warm them up with a foot soak and bundle them up with nice thick socks before you go to bed. It is critically important that you do this. I wrote more about the floor side of this in Is Walking Barefoot at Home Bad?

    Does cold feet mean a cold uterus?

    In Chinese medicine, cold feet and a cold uterus are closely linked. When you have cold feet, that cold travels up to your legs, your lower back, and yes, your uterus. The reel is right about this, and it is why the advice is given especially to women.

    The road from the feet to the womb

    Follow those three yin channels. They rise from the feet up the inner leg and gather in the lower abdomen, where they meet at Sanyinjiao, SP6, "Three Yin Intersection," just above the inner ankle, one of the most used points for women's health. The Liver channel circles the genitals. The Kidneys, the root of the body's warmth, govern the lower back and reproduction. And the Chong and Ren vessels, the channels of menstruation and conception, arise in the uterus itself. Cold that enters at the feet travels a short road to the place a woman most needs warm. Chinese medicine calls the result cold in the uterus: periods that cramp and ease with heat, and a lower belly cold to the touch.

    What the research shows

    Cold hands and feet are a recognized pattern in East Asian medicine, and they travel with period pain. In a Korean study of more than 6,000 patients from 25 medical institutes, those with cold hypersensitivity in the hands and feet had a higher frequency of dysmenorrhoea, painful periods, along with anaemia, low blood pressure, chronic gastritis and reflux.[3]

    Japan has its own name for the cold constitution, hiesho, and treats it as a condition of women. Japanese researchers defined it as a gap of more than 6°C between the body's core and its surface, and found that premenopausal women who ran cold through their whole cycle had higher sympathetic, fight-or-flight nervous activity than women who did not.[4]

    A meta-analysis of 96 studies covering 78,068 students found that period pain affected 66.1 percent of them, and exposure to cold and eating cold foods during menstruation were among the risk factors significantly related to it.[5] Warmth works the other way. In a randomized trial of 84 women, a continuous low-level heat patch on the abdomen relieved menstrual pain as well as ibuprofen did.[6] If cramps are your picture, read Are Bananas Good for Period Cramps?

    Gut Brain Synchrony

    Always cold? Let's find out why.

    Gut Brain Synchrony is my community on Skool: courses on gut, brain and sleep health, condition-specific programs, and weekly live Q&A with our clinical team. Your first week is free.

    Join Gut Brain Synchrony

    Why is toenail fungus so common?

    There is a reason that toenail and foot fungus is so common in the West: people ignore this kind of advice and walk around with cold feet all the time.

    Fungal nail infection is now one of the most common nail problems in the world. A 2026 meta-analysis of 219 studies put its prevalence among people tested at 22.91 percent, and at 25.90 percent in high-income countries against 17.76 percent in low-income countries. People wearing closed, occlusive footwear had a prevalence of 44.17 percent.[7]

    Why not barefoot in the shower

    A wet floor is cold and damp at once, and it is shared. In Durban, South Africa, researchers examined men who regularly washed their feet in the communal ablution areas of five mosques. Fungal infection of the feet and toenails was found in 85 percent of them, against 41 percent of office workers. Dermatophytes and yeasts grew from the floors of the ablution areas in every mosque studied, and the authors named public showers, pools and changing rooms as the same risk.[8]

    Can cold feet cause foot fungus?

    Over the long term, yes. Cold toes can lead to foot fungus, and the reason is circulation.

    01 When your feet are cold, your blood vessels constrict. This is the body's reflex for holding heat in the core. At Penn State, cooling healthy adults in a water-perfused suit cut the blood flow in the skin on top of the foot by 16 percent.[9]
    02 Your blood carries immune activity to the extremities. Less blood means less defense. In a landmark New England Journal of Medicine trial, 200 colorectal surgery patients were given either routine thermal care, which left them mildly cold, or extra warming. Wound infections struck 19 percent of the cold group and 6 percent of the warm group. The authors explained that cold triggers vasoconstriction, which lowers the oxygen in the tissue, and low oxygen impairs the ability of neutrophils, the white cells that kill invaders, to do their job.[10]
    03 Cold feet weaken defenses beyond the feet. At the Common Cold Centre at Cardiff University, 180 healthy people were randomized to have their feet chilled in cold water or not. Over the next four to five days, 13 of the 90 chilled volunteers reported a cold, against 5 of the 90 controls.[11]

    The feet are already far from the heart

    The feet are already very far from your heart. When that circulation is limited further by cold exposure, constricted vessels make it very difficult for your body to fight off mold and fungus. You can see the distance in the nails themselves. In healthy young American adults, fingernails grew 3.47 mm a month and toenails only 1.62 mm.[12] A toenail that grows slowly is slow to push an infection out.

    The link between poor circulation in the feet and fungus is well established. In 254 patients at a vascular clinic, peripheral arterial disease, reduced blood flow to the legs and feet, raised the odds of toenail fungus nearly fivefold, a risk odds ratio of 4.8.[13] Reviews in dermatology name peripheral arterial disease as an independent predictor of onychomycosis,[14] and list both poor arterial supply and chronic venous insufficiency among its main predisposing factors.[15] Feet that are cold every day live with a smaller version of the same problem.

    How to keep your feet warm at night

    01 Check your feet before bed. If they are cold, warm them before you sleep, whatever the season.
    02 Warm them with a foot soak. A basin of warm water, deep enough to cover the ankles. A 2025 meta-analysis of 18 studies in 950 adults over 60 found warm foot baths significantly improved sleep quality, with the clearest results at water no hotter than 40°C (104°F), soaks of at least ten minutes, and at least a week of the routine.[16]
    03 Bundle them up in nice thick socks. Dry them well after the soak, then put the socks on straight away so the warmth stays in through the night.
    04 Don't go barefoot on cold, hard floors. Keep slippers by the bed, so your first step in the morning is not onto cold tile or wood.
    05 Don't go barefoot in the shower. Wear shower sandals in shared showers, gyms and pools, and dry your feet and between your toes before your socks go on.

    Socks, cold feet and fungus: your questions

    Is it good to wear socks to bed every night?

    Not everybody has to wear socks to bed every night. What matters is that your feet stay warm at all times. If your feet run cold, socks every night, all year round, are a good habit.

    Why is toenail fungus more common than fingernail fungus?

    The feet are farther from the heart, shut in shoes all day and most often cold. Less circulation means less immune activity reaching the toes.

    Why am I prone to toenail fungus?

    Look at how often your feet are cold or damp. Constricted vessels in cold feet make it very difficult for your body to fight off mold and fungus. Warming your feet every night is where to start.

    Your feet are a gateway. Keep them warm.

    — Brehan Crawford, L.Ac.

    Gut Brain Synchrony

    Warm feet are a start. Let's find the rest.

    If you are always cold, sleep badly or keep fighting the same problems, the cause is rarely one thing. Inside Gut Brain Synchrony you get courses on gut, brain and sleep health, condition-specific programs and weekly live Q&A with my clinical team.

    Start your free week

    Your first week is free.

    References

    1. Ko Y, Lee JY. Effects of feet warming using bed socks on sleep quality and thermoregulatory responses in a cool environment. J Physiol Anthropol. 2018;37(1):13. doi:10.1186/s40101-018-0172-z
    2. Kräuchi K, Cajochen C, Werth E, Wirz-Justice A. Functional link between distal vasodilation and sleep-onset latency? Am J Physiol Regul Integr Comp Physiol. 2000;278(3):R741-R748. doi:10.1152/ajpregu.2000.278.3.R741
    3. Bae KH, Go HY, Park KH, Ahn I, Yoon Y, Lee S. The association between cold hypersensitivity in the hands and feet and chronic disease: results of a multicentre study. BMC Complement Altern Med. 2018;18(1):40. doi:10.1186/s12906-018-2082-3
    4. Kono K, Abe S, Yamamoto M, et al. Vascular endothelial dysfunction and autonomic nervous hyperactivity among premenopausal women with cold-sensitivity constitution (Hiesho). Tohoku J Exp Med. 2021;253(1):51-60. doi:10.1620/tjem.253.51
    5. Wang L, Yan Y, Qiu H, et al. Prevalence and risk factors of primary dysmenorrhea in students: a meta-analysis. Value Health. 2022;25(10):1678-1684. doi:10.1016/j.jval.2022.03.023
    6. Akin MD, Weingand KW, Hengehold DA, Goodale MB, Hinkle RT, Smith RP. Continuous low-level topical heat in the treatment of dysmenorrhea. Obstet Gynecol. 2001;97(3):343-349. doi:10.1016/s0029-7844(00)01163-7
    7. Wongyikul P, Lumkul L, Preechasuth K, Phinyo P, Chieosilapatham P. Global and regional prevalence, aetiology and socioeconomic distribution of onychomycosis: a systematic review and meta-analysis (2013-2023). J Epidemiol Community Health. 2026;80(8):576-583. doi:10.1136/jech-2025-224978
    8. Raboobee N, Aboobaker J, Peer AK. Tinea pedis et unguium in the Muslim community of Durban, South Africa. Int J Dermatol. 1998;37(10):759-765. doi:10.1046/j.1365-4362.1998.00550.x
    9. Greaney JL, Kenney WL, Alexander LM. Neurovascular mechanisms underlying augmented cold-induced reflex cutaneous vasoconstriction in human hypertension. J Physiol. 2017;595(5):1687-1698. doi:10.1113/JP273487
    10. Kurz A, Sessler DI, Lenhardt R. Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization. N Engl J Med. 1996;334(19):1209-1215. doi:10.1056/NEJM199605093341901
    11. Johnson C, Eccles R. Acute cooling of the feet and the onset of common cold symptoms. Fam Pract. 2005;22(6):608-613. doi:10.1093/fampra/cmi072
    12. Yaemsiri S, Hou N, Slining MM, He K. Growth rate of human fingernails and toenails in healthy American young adults. J Eur Acad Dermatol Venereol. 2010;24(4):420-423. doi:10.1111/j.1468-3083.2009.03426.x
    13. Gupta AK, Gupta MA, Summerbell RC, et al. The epidemiology of onychomycosis: possible role of smoking and peripheral arterial disease. J Eur Acad Dermatol Venereol. 2000;14(6):466-469. doi:10.1046/j.1468-3083.2000.00124.x
    14. Faergemann J, Baran R. Epidemiology, clinical presentation and diagnosis of onychomycosis. Br J Dermatol. 2003;149(Suppl 65):1-4. doi:10.1046/j.1365-2133.149.s65.4.x
    15. Tchernev G, Penev PK, Nenoff P, et al. Onychomycosis: modern diagnostic and treatment approaches. Wien Med Wochenschr. 2013;163(1-2):1-12. doi:10.1007/s10354-012-0139-3
    16. Chang SY, Lee YC, Hung HY, Chen CT, Fang CJ, Chen YC. A systematic review and meta-analysis of footbath effects and optimal procedures to improve sleep in older adults. Scand J Caring Sci. 2025;39(3):e70118. doi:10.1111/scs.70118