Why does my normal body temperature always seem to be lower than 98.6 degrees? By how much do normal human body temperatures vary?

- Asks Lev from Detroit, MI

Normal body temperature can vary slightly from person to person. [Credit:Xavi Sanchez]
By | Posted January 2, 2008
Posted in: Ever Wondered?, Health
Tags: , ,

When the German physician, Carl Wunderlich, first reported 37 degrees Celsius (or 98.6 degrees Fahrenheit) as the average human body temperature in 1861, he claimed to have drawn his conclusion from more than a million armpit measurements of 25,000 patients. As unlikely as that sounds, it’s true that “normal body temperatures” are largely based on observation, and not any comprehensive theory.

In fact, normal body temperature not only varies between individuals, but also flutters within the same person with time of day and age, usually between 96.9 °F and 100 °F.

If you measure your own temperature at different parts of the body, say in your mouth and under your arms, you’ll notice that the temperatures are different. The general rule is that the thinner a body part is, the less contact it has with the outside environment, and therefore the higher temperature you’ll observe.

As with all other mammals, humans maintain a relatively constant temperature by breaking down carbohydrates, proteins and fats for energy, much like a power plant that burns coal for energy. The process occurs inside our cells, where oxygen, water and nutrients chemically react to produce carbon dioxide, energy and heat. That heat is then absorbed by blood and distributed throughout the body via a network of veins, arteries and capillaries.

The elasticity of those capillaries plays a central role in our ability to maintain constant body temperatures. When there’s too much heat in the body, our capillaries automatically expand and increase the blood flow to the skin, allowing the excess heat to transfer to the air. This is why people become flushed after working out. Conversely, when we don’t have enough energy to balance out the heat loss, capillaries narrow to slow down the blood flow and therefore minimize energy escape.

However, not all fluctuations of our body temperature fall under the control of blood vessels. For example, you are likely to have a higher temperature right after a 100-meter sprint than when you are fast asleep. Intense physical activities temporarily boost your metabolic rate as your body burns more fuels to balance your energy consumption.

Body temperatures wax and wane with hormone levels, too. That’s why a woman’s basal body temperature, or her temperature on waking after a normal night’s sleep, is often used as an indicator of ovulation. Characterized by the surge of luteinizing hormone, a kind of hormone needed for proper reproductive function, ovulation usually increases basal body temperature by 0.4 °F to 1 °F.

Women also tend to have higher rectal body temperatures, or temperatures taken directly inside the body cavity, than men, according to a 2001 study by a group of Dutch scientists. They largely attributed the difference to women’s reproductive cycle, which may in turn explain why men and women have slightly different ways to maintain their body temperatures. Other possible explanations include different abilities to contract blood vessels and differences in resting metabolic rates.

Meanwhile, controlling body temperatures has recently emerged as a potential treatment for stroke. Clot-causing cells, the main culprit for blocking blood vessels and inducing stroke, were found to be less active at lower temperatures. The commonly accepted target temperature is now set at 91.4 °F, or 33 °C, but clinical trials are still underway in the search for optimal conditions for treatment.

While those treatments require a change in body temperature, it is generally true that a healthy person will have a fairly constant body temperature. In fact, it’s so important that your body spends 90 percent of its metabolic energy to make very sure that your temperature is as close to 98.6 °F as possible. So, even though you may feel hot or cold, or worry that your body temperature isn’t 98.6 °F all the time, rest assured, your body is working very hard to maintain that temperature.

Related Posts


comments

All comments are moderated, your comment will not appear on the site until it has been approved.

  1. Why am I always feeling so cold? I put on layers of clothing and even in rooms or places where others have only a t-shirts or so I seem to need at least a t-shirt and sweatshirt or sweater and even then often am cold. Also very often have cold feet. Thank you Rennie

    rennie boersma, January 25, 2008 at 2:29 pm
  2. at 69 my temp is 96.6-i take diovan 320mg to lower my bp.since its purpose is to push circulation to extremities could this explain my low temp.

    moore, January 30, 2008 at 3:17 pm
  3. age 77, tend to have oral temps in the 97′s. If temp goes to 98.8 or higher, I feel as if I have a fever–zlight dizzyness, ‘spacey’ feeling, a bit of balance trouble. But doc says no fever unless temp hits 100.4. Can one have a fever with a lower temp as I feel I do?

    Constance Eves, March 17, 2008 at 12:24 pm
  4. I am no doctor but dont somone of your age normally run a lower BP rate anyway? That would explain why you feel this way when your is higher that usual.♥

    Shannon, March 18, 2008 at 5:09 pm
  5. There is a lot of undiagnosed hypothyroidism out there! I had all kinds of wierd symptoms, twitching, sweating, cold, dizzy, weak and fatigued, and was told my thyroid was just fine.
    Then I got worse and in an emergency room was told my thyroid was not fine, but “sometimes the problem doesn’t show up on the tests for awhile.”
    I got a ton of info from a site called
    stopthethyroidmadness.com. The blood tests are by no means always accurate and synthetic thyroid sucks, to sum up.

    Patricia, March 31, 2008 at 6:17 pm
  6. I am 71. I find my temperature varies between 96-97 to 98.6 to 99. I feel feverish at 98.6 with body ache, aching backbone, do not feel like taking bath etc. I feel OK when temp around 97.6/98.
    Naturally I have other multiple problems eg Apical Hyperotrophy, Diastolic Dysfunction, Hypertension, 40% heart blockages, Autonomous Nervous Dysfunction more at rest, peripheral neuropathty, dymelating, cervical, lumber and bent tail bone with denegeration of Discs, sensitive to gluten!, reducing caffeine tp reduce irritation of bowels, poor ballder pump with pain, simple kidney cyst Lt, frequent urination with disturbed sleep: Surgeries done tonsils, appendix, prsotrate, both inguinal hernias, urethera strictures, and bladder neck,frequent urination catarcat surgeries, high and low sugar varying between 71 to 260 with 4hours TT but controlled with food intake at medication, no thyroid problem , no HIV, no PSA, and so on.
    Medication for heart and sugar and other from time to time.

    Basic irksome problem is this low grade fever?

    Prem P Batra, April 6, 2008 at 1:24 am
  7. My husband is suffering (for about 2 yrs. from what seems to be a malfunctioning temperature gauge. He goes from hot to cold in a mattter of minutes. Has anyone suffered from this?

    Colleen Brown, July 31, 2008 at 5:13 pm
  8. I’d like to know also why I’m always cold. I used to have this furnace that kept me warm and it seems once I hit puberty hit, the pilot ligh went out.

    Megan, September 4, 2008 at 6:13 pm
  9. My temperature has dropped to 97.7 most of the time. I was at the doctor and he said he gets very few patients with a temp. of 98.6 anymore. Most are running lower temps. This seems strange/ what is causing this?

    kaci, October 14, 2008 at 8:33 pm
  10. I’m in good shape and have great health, but I am constantly colder than everyone else. I wear layers or have a blanket when others are in shorts and t-shirts. Why is this?

    Joy Hales, October 15, 2008 at 10:50 pm
  11. I actually run quite cool for my age, I’m normally 95.6 – 96. I’ve lived in the desert all my life and I’m quite happy to wear short sleeves and shorts in 55 degree weather, but I can’t stand temps above 85 degrees (ironic to where I live). I’m just curious, does having a cooler temp then the average Joe affect my tolerance for cold or hot temperatures?

    Cally, December 14, 2008 at 1:19 am
  12. Please, please, please, could you send me a copy of this article. I have a longstanding debate with a collegiate.

    Leslie Chevalier, January 5, 2009 at 5:51 pm
  13. Can you help me find information on the individual differences in normal human body temperature circadian fluctuations. Thank you in advance. Best regards.

    miroslav, February 13, 2009 at 1:11 pm
  14. In reply to Colleen Brown,July 31st, 2008 at 5:13 pm: I am 72. My temperature varies greatly. For example, in the past two days, it has bounced up and down repeatedly between 92.6 and 99.1. It has been doing this for over four years. No medical personel seem interested. It is driving me to distraction, literally. When at low temp extremes, it is difficult to focus, to remain physically and mentally balanced. It is ruining my life.

    Gary Burdick, May 8, 2009 at 9:09 pm
  15. @Gary Burdick:

    Highly fluctuating temperatures may be a sign of an adrenal insufficiency which is also often found with hypothyroidism.

    Google “adrenal insufficiency” or “hypoadrenalism” as a starting point.

    Of course, there may be other things but it might be a good place to start searching.

    Luke, May 13, 2009 at 1:36 pm
  16. Over the years I have noticed that my body temperature is usually around 35-36 degrees. So I can be feverish without actually reaching the classic 38-39 degree temerature. This is the same for my brother and 2 sisters, as well as my mother. Could it be a genetic thing?

    Naomi Juyn, May 26, 2009 at 10:12 am
  17. This….doesnt look like gonna be an easy biology project to copy

    Alexander, September 9, 2009 at 6:47 pm
  18. My temperature is often around 34.7 Centigrade. I recently suffered a pulmonary embolism and I wonder if there could be a correlation with my low body temperture. Cause of embolism not been established, as there is no sign of DVT. I am very fit and lead a ‘fitness oriented lifestyle’. Any ideas?

    Roman, December 3, 2009 at 3:12 pm
  19. why am i more colder in warm weather than hot

    thomas kitching, December 6, 2009 at 8:40 am
  20. Cold feet and generally feelng cold are often associated with low thryoid function in one form or another. Also, low adrenal function is another cause, especially the hot to cold in minutes thing. http://thyroid.about.com/ has a list of Thyroid doctors throught the word. Most of these docs will also deal with any other endo things going on, ie. Low hormones, adrenals etc. Most endo issues has a cascading effect. If one is out, then they push the other ones, like adrenals etc and they usually have to be treated as a unit. I have Hashimotos and only go to a person on these lists. Also, StoptheThyroidMadness.com is a brilliant site.

    Meg Amor, January 22, 2010 at 3:56 pm
  21. Why is a baby’s skin temperature different than their under arm temperature, when under an infant warmer?

    j. frentzel, February 3, 2010 at 10:49 am
  22. I am 59 years of age, a woman, with osteoarthritis, and “onion skin.” For the past 10 years, when I’m ill enough to not work, my temperature it is always below 97F, typically 96.6F though it has dipped to 95.3. Why does this happen to me?

    C. Rakes, March 3, 2010 at 7:15 am
  23. Hi, my daughter is now 8 years old and she has always had a low temp 35 celsius. I worry about it and doctors dont do anything about it. She was a premi baby 5lb. What should I do?

    s. foster, March 18, 2010 at 6:25 am
  24. Age 18, student, For older aged people it is normal for your average body temp to drop. I read on http://www.health.harvard.edu/press_releases/normal_body_temperature and it said that which i have mentioned above. check it out for yourself! it was pretty interesing!

    Student, March 27, 2010 at 2:35 pm
  25. When my daughter really feel bad thier temp runs very low. Example 96.2 and she feels bad. Her dad was the same way. They never ran 98.6. Is low temp bad?

    L Odum, May 3, 2010 at 1:51 am
  26. when my daughter (20 yrs old) runs fever 96.2 she is feeling bad. Her dad always ran a low grade but be sick. If thier temp went to 99 they would be very ill. Is there a problem here.

    L Odum, May 3, 2010 at 1:55 am
  27. I have adrenal insufficiency and hypothyroidism and have a genetic tendency to chronic low grade infections. According to the environmental doctor I see this is why my temperature stays lower than normal and spikes high or very low. Low ongoing metabolic rate + recurring infections. I have found many health professionals minimize the temperature issues I have but I have found one now who is educated enough and sensitive enough to do the right tests and acknowledges the day to day difficulties associated with it. Please get good health advise. When cold, support yourself to get your temperature up, when high get it down when possible. Hormonal tests might help and protecting yourself from chemical toxicity (chemical poisoning can cause disrupted hormonal system).

    Jess, September 10, 2010 at 1:55 am
  28. I have low body temperature and low blood pressure. I am ALWAYS cold, a lot colder than most people are. Especially my hands and feet. I always wear so many layers of clothes and I am still cold. I would love to see how all of this correlates. If the being cold, low body temperature, and low blood pressure all have something to do with each other.

    Sigvaris, November 4, 2010 at 1:47 pm
  29. everyone should perform more oral sex, it assists in raising your body temperature. Scientific fact, ask your doctor.

    Sincerely,

    Joe Schmo

    JOe Schmo, December 27, 2010 at 7:32 am
  30. Iam 65 years old and am always cold. At this moment it is 80 in my office and my hands and feet are cold. I am always colder than people I know. At this writing my temperature is 95.9. As of my last blood pressure testing, it was normal. Also the latest blood test for choresterol was normal. I also had a throid blood test T3, T4 and it came back normal. I am still in menopause and have had hot flashes for the last 8 years. I am not taking any hormone medication.

    Barbar Koehn, January 3, 2011 at 4:18 pm
  31. Why am I always feeling so cold? I put on layers of clothing and even in rooms or places where others have only a t-shirts or so I seem to need at least a t-shirt and sweatshirt or sweater and even then often am cold. When I get cold is easy to get sick ( flu) Also very often have cold feet. Thank you

    NgoVan Nguyen, August 18, 2011 at 4:24 pm
  32. I would like to know why i am always HOT .. I’ve been this way for years – at least 15. My body weight has changed during this time, but I am always hot. No diabete, been tested. Hands and feet will swell and hurt. Please, any information is welcome.

    Deby, September 9, 2011 at 4:04 pm
  33. what is the reason for different temperature in human and man

    indra, September 12, 2011 at 8:00 am
  34. I am 21 and just took my temperature and it was 95.1 … I am very cold. I am shivering and want to go to bed (but have lots of homework. why is my temperature so low? I feel like I should go see a doctor.

    annie, September 16, 2011 at 1:11 pm
  35. I thought I was going crazy- now I know it’s not that uncommon.

    Kris, October 4, 2011 at 2:47 pm
  36. What is the reason,when the body is feeling very cold,then,after an hour feeling so,hot.then again feeling cold?i almost feeling like that,for almost
    two months,So,thinking maybe it’s a symptoms of sickness?im worried about my health..

    Teresita G.Marcaida, October 11, 2011 at 4:32 am
  37. I’m 34 y.o. healthy female. My normal basal temp has always been 96.6-96.8 (97.2-97.3 during ovalution, usu. fluctuate less than .2-.4 through the day) since teenager years. I have a cold (or flu?) right now. My current temperature is 98.4 and I feel like crap with headache, chills, severe body ache, dry cough, sore eyes, nausea and sinus pain. This has been going on for the past three days when I often find myself in shivering chills since late afternoon/early evening everyday. When I use my own hands to touch my forehead, I feel like I’m undoutedly having a fever. But when others touch me, they think I’m fine. And I’m not feeling fine at all. Anyway, if my temp gets to 99 tonight, I’ll take Tylenol to get some relief whatever others say. You know your own body best and should trust yourself to judge whether you have a fever or not based on your feelings. And my TSH is normal – not sure what’s up with the low basal temp.

    Annie, October 13, 2011 at 12:35 am
  38. IF I HAD A TEMP OF 98.6 I WOULD HAVE TO BE RUSHED TO THE HOSPITAL AS HAVING A VERY HIGH FEVER,I AM COLD MOST OF THE TIME EVEN WHEN OTHERS AROUND ME ARE VERY WARM. TO DAY I WAS CHECKED MY TEMP, WAS 93,I AM 83 AND I FEEL GREAT I GUESS I WILL END UP AS THE COLDEST CAT IN THE GRAVE YARD.

    KEN POMEROY, October 16, 2011 at 10:31 am
  39. MY basal temperature is lower than it should be, but on evening I have perfect body temperature. Any reason?

    Matthias, November 5, 2011 at 3:06 pm
  40. I’m 14 and I’ve always had a temperature of 96.4. when I’m at school and I feel like I have a fever, they take my temperature and it reads 98.9 and they are like, ” Oh it’s fine” and then shove me out the door:(

    Marissa, November 8, 2011 at 5:33 pm
  41. What is your blood type? If type negative more likely your body temperature will be low. The problem is general medicine will not recognize the difference between
    Positive and negative type and will stick you with all them symptoms …results will follow

    john, December 26, 2011 at 11:18 am
  42. Mt body temperature has been low for many years ranging from96.2 to 97.2 and my docotr has never seemed to worry about it. I find it odd to have such a low temperature since I live in Florida and it rarely gets cold here. But when it does the wind makes it even colder. I read every post and it seems like a lot of people have lower than normal budy temps. I am going to the ER today for a pain under my right ribs hopefully it is only my gallbladder. Im not looding forward to THE SURGERY BUT i WOULD BE GLAD FOR THEM TO REMOVE IT, AND HOPE THAT IS ALL IT IS. Wish me kuck and pray it isnt Cancer im 53 and lost my son in 2005 to brain cancer I prayed to God to take it all away from my son and give it to me,But that isnt how it works. Good luck to everyone,, Linda

    Linda, December 26, 2011 at 4:03 pm
  43. I hope everyone has turned out well and it wasnt anything that couldnt be fixed. Sincerely Linda

    Linda, December 26, 2011 at 4:06 pm
  44. I’m 26 I’ve always ran 97.6. I know when I’m sick unfornatly drs dont alwys cause of the 98.6 or whatever thing they think nothing of it for me thats low grade fever if it hits 99 f or greater I feel pretty miserable. at 102 I often hallucinate I’ve gotten use to drs being pretty useless until temp reaches 103-104 unforntly at that point even though I may or may not be able to communicate I’m not really their. Drs really need to learn that a fever is diffrent fkr each person and adress that as it comes to better treat patients before bad things happen.

    Amanda-Beth, February 12, 2012 at 3:18 am
  45. I am 31 yrs. old my body temperature is lower then 1 or 1.2,1.5 it fluctuates between 1 and 1.5. I also feel cold while other wear half shirts I need light sweater. Also I sweat heavy.

    Aasish Rai, April 28, 2012 at 2:02 am
  46. Well there seem to be two types of people with low body temp. most of the time
    1) Who feel normal/hot (not hot to touch- they are usually cold to touch) while others are feeling cold/comfirtable [I AM ONE OF THESE]
    These are those whose body’s internal thermostat is set at a lower than normal
    temp. so compared to the body the ambient temp. wud b relatively higher for
    them than others.
    2) Who feel cold while others are comfirtable
    These are those whose thermostat is set normal but body is unable to bring up the temp. to the set normal due to some prob. in metab. eg. hypothyroidism

    Wrtiting this comment at a temp. of 97.4 F and feeling feverish enuf to take a leave (I m a medical student) nd not do nethng

    Varidh, May 20, 2012 at 10:45 pm
  47. I fixed my body temperature from 35.8C to 37C eighteen months ago.
    Read my story

    normalbodytemp.co.uk

    Janey

    Janey Hood, June 23, 2012 at 1:33 am
  48. OOps I meant
    normalbodytemperature.co.uk
    Sorry!!
    Janey

    Janey Hood, June 23, 2012 at 1:34 am
  49. I want to know why a older person has low Temperature and how come its so
    low for a older person and is because of heat when its hot outside hope
    you can find me some anwers

    Ida, September 1, 2012 at 9:44 am
  50. I am about to turn 18 years old and my normal body temperature is about 95.1. Why is it so much lower than normal?

    Alyssa, November 15, 2012 at 6:37 pm
  51. Why do people keep complaining here when nobody is answering? I have fibromuscular dysplasia and there’s no cure. I was just wondering if a circulatory problem was causing a low temp reading. I Have multiple brain aneurysms…already know I’m dying…oh well.

    Jene, November 21, 2012 at 6:25 am
  52. Why am do i always feel so hot? My siblings and mother always said i radiated heat ever since i was a child. Im 18 years old and im a female. Im not overweight. Diabetes, high blood pressure, chrones, and graves disease run in the family. But im the only one who is always hot. Can anyone enlighten me please?

    Anna, December 18, 2012 at 11:49 pm
  53. Hi ever since I was a child my temp has been constant 87 degrees ive always been healtyh n athletic tho I’m 21 now nothing has changed I have a strong immune system and only catch 1 virus a year on average I also heal pretty quickly Wat do u think?

    rolo, January 26, 2013 at 12:28 am
  54. If you look on the Internet for Hypothyroidism you will find signs of low body temperature. Generally, the average temperature of an adult with a healthy thyroid and a healthy metabolism is 98.6 degrees Fahrenheit or 37.0 degrees Celsius, and that occurs around mid-afternoon or 3 pm. So if you take your mid-afternoon temp and find it in low 98′s or even in the 97′s, you have been given a strong clue that you may be hypothyroid. And a few report their mid-afternoon temp being in the 96′s. BRRRR.
    Another temperature clue occurs first thing in the morning before you raise from your bed. Dr. Broda Barnes, a doctor who paid attention to clinical presentation and prescribed the pre-reformulated Armour, found that a healthy before-rising morning basal temp should be between 97.8 – 98.2. If it’s higher, you may be hyperthyroid, and if it’s lower, you are most likely hypothyroid. He also recommended under-the-arm temperature testing, but patients have found oral to be just as effective.

    Once you are on natural desiccated thyroid or T3-only, and are consistently raising your doses, you will see your temps climb to healthy levels with increasing feel-good symptoms to match. In many patients, reaching the average temp around 98.6 can happen before you are even on your optimal amount of desiccated thyroid or T3.

    Thyroid patients have found Mercury thermometer quite useful and accurate as compared to most digital thermometers. Yes, some digitals are definitely better than others. It’s also important to leave it under your tongue long enough, i.e. up to five minutes. A second alternative: a Geratherm, which is a liquid non-mercury thermometer. May be more accurate than digitals. Bulky.

    Along with Hypothyroidism there is slow metabolism and weight gain, feeling tired along with feeling cold. If you have these problems you should get your thyroids tested.

    Darlene, March 24, 2013 at 8:56 pm
  55. I believe some blood tests are not accurate…somewhere, I can’t remember where, so perhaps some blood expert can respond, I read a study where blood tests are performed and the readings/interpretation are supposed to be made after the blood is kept at body temperature, NOT room temperature…I have been diagnosed with MGUS..blood disease and am undergoing chemo…are my blood tests being conducted properly?

    howard schwartz, May 3, 2013 at 1:45 am
  56. I want answers to my question…??
    M 17 yrs old 5.1 height and weigh 57kg…
    wenever i check my temp on electric thermometer it shows me 98.9…???
    n wenever frnds hold me says ur body n hand is soo hot even i dnt hav fever…???
    i dnt knw y m always warm…
    i hav seen many frnds of myn in grlzzz…who r normal temp dey r nt at all warm…
    y is it soo…??wether its normal to hav same temp (98.9°) evry day…???
    i alwzz hav pimples on my face is dat bcoz of hot temp…
    even my back is filled wid pimples…:(
    i dnt lyk warm (hot) temp plzzz giv me some suggestion how to keep normal temp or cool body…..? :(

    shweta, May 17, 2013 at 12:27 pm
  57. We are all posting our questions, but there is no venue for answering. We can only “Post a Comment”. I guess we could post our opinions on each other’s maladies, or hope someone with the knowledge and bravery to diagnose over the internet would come along and indulge us?

    Shel, May 29, 2013 at 6:32 pm
  58. I am 23 years old and i was born with a heating condition and my normal body temp is a 97.6 and my body always over heats in the summer and all year round what is the cause of this i ha ve been trying to find out what has been causing it all my life and no one has been able to tell me and because of this condition i have had atleast 10 heat stokes in the course of 8 years and it seems like my condition is getting worse

    Wallace Schwartz Jr, June 23, 2013 at 1:43 am
  59. I have always had a lower body temp. I have had all the tests for thyroid, anemia, etc and they came out fine. When I was a kid I had a bad flu. My mother took my temperature and it read, 101, which really meant I had the equivalent of a 103 fever since my normal body temperature is around 96. That is why I started having feverish hallucinations! Over the years that reaction was consistent, anytime my temp reached over 101 I would be having the same problem. It took a while for my parent to realize what the issue was. It’s really important that doctors and nurses be aware of this. When I do go to the doctor when I’m sick, I’m reporting to them that I have a fever, but they rely on that “average” as if it’s supposed to be the same for everyone and then they tell me it’s impossible I have a fever because my temperature is reading 98, not recognizing that I’m there at the doctors because I’m sick with a fever-who goes when they are well after all! My greatest concern is god forbid I have to go to the hospital or a nursing home, they might take my temperature and not realize I have a severe infection of fever because they don’t ask you what your base temperature is.

    C, June 24, 2013 at 11:33 pm
  60. Having read this I believed it was extremely enlightening.
    I appreciate you taking the time and effort to put this short article together.
    I once again find myself personally spending way too much time both reading and leaving comments.

    But so what, it was still worth it!

    Dawna, March 27, 2014 at 3:25 pm
post your comment