Too Cold? Too Hot? How Does The Thyroid Affect Body Temperature?

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While external temperatures certainly have an impact on whether a person is hot or cold, there are certain conditions that can actually affect the sensitivity of the human body to certain temperature conditions.

This may cause a person to feel cold even when it is room temperature or perhaps even hot. On the other hand, a person may also feel hot even while exposed to colder temperature conditions.

The Thyroid gland has many functions in the body, and various studies have shown that this particular gland that forms part of the endocrine system plays a role in internal temperature regulation. When issues arise with the Thyroid gland and the production of the hormones secreted by this structure, then temperature perception may be altered.

When there are too many Thyroid hormones in a person’s body, it is possible for the individual to feel like they are hot all the time. On the other hand, when levels of these hormones decline too much, then the person may rather feel cold all the time.

The Thyroid Gland And Thyroid Hormones

The Thyroid gland, as previously stated, is a part of the endocrine system. This system holds various glands that secrete hormones, which are essentially chemical messengers that help the body function normally.

The Thyroid gland, in particular, excretes two important hormones into the bloodstream, which then assists in the regulation of metabolism – both general metabolism and cellular metabolism are affected by these hormones.

The two primary hormones that are produced and secreted by the Thyroid gland include Thyroxine and Triiodothyronine1. Thyroxine is commonly known as T4 as well, while Triiodothyronine is often called T3.

The secretion of these hormones is regulated by a hormone known as the Thyroid Stimulating Hormone or TSH. This hormone is secreted by the Pituitary gland, yet another structure that is part of the endocrine system.

The Thyroid Gland And Body Temperature

Studies have found that various factors can cause a change in body temperature – including a fluctuation of Thyroid-related hormones.

Additionally, it is also important to note here that studies also confirmed that a change in body temperature caused by conditions not directly related to the Thyroid gland might also have an impact on hormones secreted by this gland.

Thus, the connection is somewhat complex – but let us explore it in more detail by exploring several different studies researched on this topic.

In one study2, scientists measured the effect that a change in internal body temperature caused by non-Thyroid related conditions had on Thyroid hormones. A total of 49 patients were analyzed during this study. All patients had hyperpyrexia, or a high fever, which leads to an elevation in internal body temperature.

None of the patients had any existing Thyroid-related disease, and they were considered euthyroid, which means they had normal functioning Thyroid glands. The researchers discovered that as the body temperature of the patient increased due to fever, circulating serum Triiodothyronine, or T3, levels started to decrease.

More recent studies have provided evidence of how Thyroid hormones may have a direct impact on internal body temperature. Research is still ongoing to determine the specific physiological role that the Thyroid and the hormones produced by the gland has on temperature regulation, but several discoveries and theories have already surfaced.

In one study3, scientists explain the secretion of Thyroid hormones has an impact on the stimulation of certain enzymes, as well as the ability to alter the consumption of oxygen in the body. In particular, an enzyme known as mitochondrial 3-phosphate glycerol dehydrogenase is stimulated by Thyroid hormones. Lipogenic enzymes also seem to be affected by the presence or absence of Thyroid hormones. It has been suggested that the stimulation of these enzymes causes an increase in aerobic metabolism rate, as well as heat production. In the absence of these hormones, the inability to stimulate the enzymic activity may, on the other hand, lead to the inability to produce the required heat in a cold environment effectively.

A scientific publication4 by the American Physiology Society explains that for hormones produced by the Thyroid to be effective in regulating metabolism and other factors, a conversion from Thyroxine to Triiodothyronine is required.

Thyroxine is not considered the active form of Thyroid hormones, but rather Triiodothyronine. For this conversion to be possible, there is a need for 5deiodinase type 2, also called D2. The D2 expression has been found to be active in various parts of the human body. The publication explains that D2 has been identified in skeletal muscle tissue, brown adipose tissue, white fat, and even I the hypothalamus.

The conclusion here is that adaptive thermogenesis regulated by the active form of Thyroid hormone, Triiodothyronine, is a systematic process that occurs in different tissues throughout the human body.

Too Cold? Hypothyroidism May Be To Blame

Hypothyroidism is a term used to refer to a decline in Thyroid hormones in the human body. The condition is often caused by factors that lead to a dysfunction of the Thyroid gland, causing the gland to secrete too few hormones. This can lead to a deficiency in Thyroid hormones. However, there are ways to naturally increase thyroid hormone levels and thyroid function.

When there are not enough of these hormones in the human body, then a patient may start to find that they become more sensitive to cold temperatures. This is due to the body’s inability to active its adaptive thermogenesis process, which causes an increase in internal temperature in response to external temperature conditions. This process relies on the presence of Thyroid hormones, with a particular focus on Triiodothyronine.

Simply having a decrease in the tolerance to cold temperatures is certainly not enough for a physician to diagnose a patient with Hypothyroidism. The physician needs first to understand the additional symptoms that the patient is also experiencing.

Apart from the sensitivity to the cold temperatures, other symptoms that the physician may look out for include5:

When the patient experiences some of the above-mentioned symptoms, in addition to the cold intolerance, then the physician may recommend certain tests to be conducted on the patient. Hypothyroidism cannot be diagnosed through a physical examination and asking the patient about their symptoms alone.

Blood tests need to be done. A blood sample will be collected from the patient. The sample is sent to a laboratory, where scientists will test for levels of Thyroid hormones in the patient’s blood. Additional tests may be requested to determine levels of TSH in the blood of the patient.

When Thyroid hormone levels are below the normal levels, then the patient will be diagnosed with Hypothyroidism. It is also important for the physician to understand the possible cause behind the disorder. Hashimoto’s disease is very common and leads to the immune system attacking the Thyroid gland.

The diagnosis will be followed by appropriate Thyroid hormone replacement therapy. Levothyroxine is currently the recommended treatment protocol for patients who have been diagnosed with Hypothyroidism6. This is a synthetic type of Thyroid hormone that can help to balance these hormones in the patient’s body.

It is important that a physician explains to the patient that the dosage may be experimental during the early stages of treatment. An appropriate dose will be prescribed but may be altered in the first few weeks or months while the patient is treated to help balance their Thyroid hormones without causing significant adverse effects.

Too Hot? Hyperthyroidism May Be The Culprit

While Hypothyroidism is known to reduce a patient’s tolerance to cold, Hyperthyroidism is rather known to cause a patient to feel hot most of the time. The increase in internal body temperature is primarily caused by elevated levels of Thyroid hormones. This, in turn, leads to an increase in the activation of thermogenesis within the human body. The result would be a higher temperature – causing a person to feel hot, even when the external temperature is on the colder side.

Similar to Hypothyroidism, a complete analysis and examination of the patient are required before they can be diagnosed with Hyperthyroidism. The physician will conduct a physical examination – and also feel if there may be physical changes in the patient’s Thyroid gland. The physician will also ask the patient about additional symptoms that they might be experiencing.

Symptoms associated with Hyperthyroidism, apart from the increased sensitivity to heat, include:

  • A rapid and irregular heart rate
  • Heart palpitations
  • Tremors
  • An increase in bowel movements
  • Fatigue
  • Weakness
  • Weight loss
  • Increased sweating

In case the patient shows these additional signs, the physician may proceed with a series of blood tests. Blood tests will look at Thyroid hormone levels that are circulating in the patient’s bloodstream. If levels of these hormones are higher than what is considered normal, then the patient will likely be diagnosed with Hyperthyroidism.

In some cases, the doctor will conduct additional tests to determine the cause of the Hyperthyroidism. An autoimmune disease known as Graves’ disease is known to be a relatively common cause for this Thyroid-related disorder. There are, however, other possible causes as well.

Treatment depends on the patient’s unique condition. The cause of the Hyperthyroidism will play a role in determining what type of treatment method would be most effective to assist in balancing the patient’s Thyroid hormones. In the case where there is an overproduction of Thyroxine and Triiodothyronine in the Thyroid gland, the patient is likely to be prescribed antithyroid drugs7. These help to reduce the activity of the Thyroid gland, bringing levels of Thyroid hormones into a better balance.

Treatment sometimes also include the use of Radioactive iodine ablation, which is quite a popular treatment option among patients in the United States. In some cases, surgical thyroidectomy may also be a preferred option, but this holds the risk of causing the development of Hypothyroidism in the patient.

Since each treatment has both pros and cons to be taken into account, it is important that both the physician and the patient considers all options that are available. The patient should be educated on each of the treatment options that they can opt for – and they should thoroughly understand any particular risks associated with these methods. The most ideal treatment plan will then be prescribed to the patient to assist in the management of Hyperthyroidism.


Thyroid hormones have been shown to have a role to play in the regulation of the body’s internal temperature. Research suggests that low Thyroid hormones make a person more sensitive to cold temperatures, while an elevation in these hormones causes an intolerance to hot temperatures. When an intolerance is developed to a particular temperature, be it heat or cold, not enough evidence is available to diagnose a patient with a Thyroid disorder, but tests are in order to assist in understanding if Thyroid-related hormones may have a role to play in these symptoms.


1 M.A. Shahid, S. Sharma. Physiology, Thyroid Hormone. StatPearls. 23 Mar 2019.

2 J.G. Ljunggren, G. Kallner, M. Tryselius. The effect of body temperature on thyroid hormone levels in patients with the non-thyroidal illness. Acta Medica Scandinavica. 1977.

3 J. Enrique Silva. The multiple contributions of thyroid hormone to heat production. The Journal of Clinical Investigation. 1 Jul 2001.

4 R. Mullur, Y.Y. Liu, G.A. Brent. Thyroid Hormone Regulation of Metabolism. American Physiological Society: Journal of Physiological Reviews. 1 Apr 2014.

5 K.T. El-Shafie. Clinical presentation of Hypothyroidism. Journal of Family & Community Medicine. 2003.

6 A.J. Chakera, S.H.S. Pearce, B. Vaidya. Treatment for primary hypothyroidism: current approaches and future possibilities. Dovepress: Journal of Drug Design, Development and Therapy. 22 Dec 2011.

7 I. Kravets. Hyperthyroidism: Diagnosis and Treatment. Journal of American Family Physician. 1 Mar 2016.

1 Comment
  1. Reply
    Laurie Weaver June 4, 2021 at 12:38 pm

    I have had low thyroid since becoming post menopausal in 2009. Every summer here in the south, where it is 90 plus degrees in July and August, I had all eight symptoms of heat exhaustion multiple times every summer for several years until I went to the doctor and found I had low thyroid. Your article says basically if thyroid low can’t tolerate cold and if high can’t tolerate heat. With my low thyroid I had problems with cold but more severe problems with heat.

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