Jun 22, 2021

6 min read

Why am I so hot all the time? 10 Conditions that cause heat intolerance

We all have that one friend who shows up to parties in the middle of summer in a sweater and a beanie. After all, it doesn’t take a scientist to know that individual preferences for temperature may vary. How hot or cold we feel at any given temperature setting, is a function of our body’s unique constitution.

In most cases, feeling a bit toasty when others around you seem to be comfortable, is nothing to be alarmed about. Your metabolism might just be running a bit warmer than others’. However, if you constantly feel too hot for comfort and feel like you are always close to breaking a sweat, you might need to check with your doctor to find out if you have an underlying condition that’s causing your symptoms.

A number of conditions could cause you to feel uncomfortably hot, even if the ambient temperature is normal or cool. Here, we explore a few of the reasons why you might be feeling hot:

1. Stress and Anxiety

Let’s start off with the most obvious and least worrying reason for why you might be feeling hot - stress. Stress triggers a rise in your body’s temperature because when your body detects a stressful or threatening situation, it activates your sympathetic nervous system, which prepares your body to deal with the situation.

Along with feeling hot, you might notice that your heart speeds up and you start sweating a bit, in moments of anxiety/panic. In most cases, these symptoms go away on their own, as and when the situation that’s causing the stress resolves.

However chronic stress, over a prolonged period of time, leads to a more long-term rise in the body’s core temperature. This is termed “psychogenic fever”. Click Here to know more about psychogenic fever and how it’s caused.

2. Thyroid Disease

The thyroid gland is one of the central players in the body’s endocrine system. The endocrine system, along with the nervous system, is responsible for synchronising and regulating the body’s functions and responses to the environment. The thyroid gland is responsible for regulating the body’s metabolism and is actively responsible for controlling a whole host of processes that are directly and indirectly connected with how the body produces and spends energy.

Hyperthyroidism refers to a group of conditions in which the thyroid gland overproduces thyroid hormones (T3, T4). These hormones “turn-up” the body’s metabolism and so, an abundance of these hormones causes a range of symptoms, among which is heat intolerance. A sure sign of hyperthyroidism is a feeling of being excessively hot and being prone to sweating. Other symptoms of hyperthyroidism include weight loss, restlessness, poor sleep, palpitations and excessive appetite. The most common cause of hyperthyroidism is auto-immune, a condition called “Graves’ disease”, in which the body’s immune cells attack the thyroid gland, causing it to produce more thyroid hormones.

If you have any of these symptoms, you need to have your thyroid function checked by a licensed healthcare practitioner.

3. Diabetes

Both type 1 and type 2 diabetes render patients unable to cope well with heat and high temperatures. Especially in patients with diabetic complications such as microangiopathy (small blood vessel damage) and neuropathy (nerve damage), a marked sensitivity to hot weather, can be observed. This is because these complications may cause damage to the sweat glands, making it harder for such patients to cool off in hot weather.

Moreover, diabetics tend to get dehydrated easily, further rendering them sensitive to the heat. This makes it imperative that they take care to hydrate themselves adequately, especially in hot weather.

4. Medications

Certain over the counter (OTC) drugs have been associated with side-effects such as excessive heating and sweating.

Common drugs that are associated with this side effect, include:

  • Zinc Supplements
  • Hormonal preparations
  • Anti-depressants like Norpramin and Nortriptyline
  • Pseudoephedrine (Sudafed) and other sympathomimetics
  • Anti-hypertensive drugs like Hydrochlorothiazide
  • Recreational drugs such as Amphetamine and MDMA

It is important to note that medications do not cause the same or all side effects in everyone who takes them. It is therefore very important to consult your physician before you start taking new prescription drugs.

5. Pregnancy

It is a commonly known fact that women experience hot flashes during menopause, due to hormonal fluctuations. However, a similar type of heat sensitivity can be experienced by pregnant women.

During pregnancy, a woman’s hormonal levels undergo dramatic fluctuations, which cause alterations to how she responds to the heat. About 35% of pregnant women report feeling excessively hot, at some point during their pregnancy.

6. Hypohidrosis/Anhidrosis

Sweating is one of the body’s key mechanisms against heating. It helps the body release heat into the surroundings and cool itself down.

Hypohidrosis refers to a condition where a person’s ability to sweat is greatly diminished. Such patients find it hard to cool themselves down, because, even when the appropriate stimuli are present in the environment to initiate a sweating response, their bodies find themselves unable to do so adequately. Hypohidrosis can occur as a result of a number of systemic, nervous or dermatological conditions. Treatment options depend on the primary cause of the condition. However, in many cases, hypohidrosis can’t be treated, unfortunately.

When the sweating response is completely absent, the condition is called “anhidrosis”.

7. Fibromyalgia

Fibromyalgia is a painful condition characterised by chronic pain in several areas of the body and a heightened sensitivity to pressure.

People with fibromyalgia tend to be quite sensitive to both extremes of weather - hot and cold. Some patients tend to report feeling worse in the hotter months and some in the colder months.

Fibromyalgia, among its other symptoms, impairs the body’s ability to adjust to different temperatures (thermoregulation). In hot weather, people with fibromyalgia find themselves excessively hot and are especially prone to heat illness such as heat stroke or rash. This is because people with fibromyalgia have reduced blood flow to the skin and therefore, do not perspire easily. Also, they tend to get dehydrated quite easily, which further contributes to heat intolerance.

8. Multiple Sclerosis

Multiple sclerosis (MS) is a very serious disease of the nervous system which can be very debilitating because of its wide range of symptoms.

Multiple sclerosis is caused by demyelination of nerves. Nerves have insulating sheaths made up of a substance called “myelin”. In demyelinating diseases such as multiple sclerosis, this sheath is damaged which leads to nerves being exposed and unable to conduct signals properly.

Heat intolerance is one of the many symptoms of MS. Because the nerves of MS patients are exposed, they are much more sensitive to heat. Even the slightest increase in body temperature is accompanied by a severe exacerbation of symptoms in these patients. Something innocuous like a hot shower or a mild workout can trigger paroxysmal flashes in these patients.

9. Age

Older people are metabolically challenged compared to their younger counterparts. Therefore, they have trouble adjusting their body temperatures to changes in external conditions.

Both extremes of weather can take more of a toll on seniors (aged 65 or above).

10. Ovarian Failure

Primary ovarian insufficiency or premature ovarian failure refers to a condition in which the ovaries cease to function adequately before menopausal age.

One of the main functions of the ovaries is to produce the female sex hormone estrogen. Without adequate amounts of estrogen, the body experiences menopausal symptoms such as “hot flashes”, ahead of time.

Women with primary ovarian insufficiency may feel excessively sensitive to hot weather. They also experience a host of other symptoms such as impaired concentration, low sex drive, irregular/absent periods etc.

About the author

Abishek Swaminathen

Senior Content Manager

Abishek is ONiO’s senior content manager. A medical doctor by profession, he stumbled onto a writing career almost by accident, as it were. Words have enthralled Abishek since the day he first held a book and at ONiO, he channels his inner wordsmith towards providing our subscribers with regular doses of fun and informative content.

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