The human body reacts to external and internal changes. It is possible to reduce body heat externally or internally. Jumping into a cool pool is an example of external cooling while drinking cold water helps reduce body temperature internally.

Experts consider the normal body temperature to be around 98.6ºF (37ºC), but it can vary by up to 0.9ºF (0.5ºC) depending on the time of day. It also differs slightly from person to person.

There are many reasons why a person’s body temperature may rise. These include illnesses, medications, and intense physical activity. A body temperature above 100.4ºF (38ºC) usually indicates fever.

Simply being outdoors on an extremely hot day can be enough to cause heat exhaustion or heat stroke. This is of particular concern around the world with the growing impact of rising temperatures due to climate change.

According to the National Oceanic and Atmospheric Administration (NOAA)’s 2021 Annual Climate Report, the combined land and sea temperature has been rising at an average rate of 0.14 degrees Fahrenheit (ºF ) or 0.08 degrees Celsius (ºC) per decade for nearly 150 years.

At the same time, a 2021 study estimates that 37% of all heat-related deaths around the world can be attributed to climate change.

This article goes into detail about the common causes of high body temperature and discusses eight tips that can help a person reduce body heat and

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Body temperature rises when the external temperature increases but also when the internal temperature increases. The human body is always regulating its temperature, and it can lower it in four different ways:

  • vaporization, which it achieves by sweating
  • radiation, which means releasing heat into the surrounding air
  • convection, which occurs when cooler air surrounds the body
  • conduction, which is the transferral of body heat into adjacent cold water or ice

A brain region called the hypothalamus is responsible for regulating body temperature. It checks the body’s current temperature against its normal temperature and then regulates it.

When the body is too hot, regulation occurs through sweating to cool it down. When it is too cold, the hypothalamus triggers shivering to warm it up.

Although it may seem counterintuitive, eating spicy foods and engaging in activities that cause the body to sweat could make it feel cooler compared to the outside temperature. This is because sweating reduces body temperature.

Below are eight tips for reducing body heat:

1. Drink cool liquids

Drinking cool liquids like water or iced tea can help reduce body temperature by cooling the body internally. The regular intake of fluids can also prevent dehydration, which can increase body heat.

2. Go somewhere with cooler air

People can reduce their body temperature by moving to an area with a cooler external temperature. The body will lose heat by convection.

3. Get in cool water

Swimming in cool water, taking a lukewarm bath, or applying cold water to the body can reduce body temperature. In these cases, body temperature will decrease as a result of conduction.

4. Apply cold to key points on the body

Applying cold water or ice to strategic points on the body where the veins are close to the surface — such as the wrists, neck, chest, and temples — can quickly lower the temperature of the blood running through these veins. This allows the body to feel cooler.

5. Move less

The body releases heat when it moves. In hot temperatures, a person is likely to feel less hot if they avoid heavy exercise and limit their movement.

6. Wear lighter, more breathable clothing

Heat passes more easily through some fabrics than others. Natural fabrics, such as cotton and linen, allow heat to escape from the body more easily than synthetic fabrics, such as acrylic and nylon.

7. Take heat regulating supplements

Depending on the cause of high body temperature, taking a supplement may help regulate body heat.

A 2018 study that compared plant extracts found that evening primrose oil and black cohosh effectively reduced the frequency and severity of hot flashes in people going through perimenopause or menopause.

Black cohosh also reduced the frequency of hot flashes.

Learn more about taking black cohosh during menopause here.

8. Talk to a doctor about thyroid health

At times, high body heat may be due to an overactive thyroid. When this is the case, a person might also notice other symptoms, such as a rapid heart rate, sweating, jaundice, and confusion.

Anyone who thinks they might have a thyroid issue should speak to a doctor.

The cause of high body temperature can be external or internal. Below, we list some of the main reasons why a person may feel hotter than usual:

Hot environment

Spending time outside in very hot weather can increase a person’s body temperature, as can being in a hot indoor environment for extended periods. Wearing too many layers in either situation can also lead to an increase in body temperature.

Overexposure to sun or heat

Spending too much time in the sun can increase body heat or even lead to heatstroke, which some people call sunstroke.

Children and older adults are particularly at risk of heatstroke. Dehydration from too much sun exposure can further increase body heat. Therefore, drinking lots of fluids and resting after prolonged sun or heat exposure is important.

What are the signs of being overheated?

Doctors categorize overexposure to heat into three levels: heat cramp, heat exhaustion, and heatstroke.

Although hard on the body, heat cramp does not require medical attention. It tends to subside with plenty of rest and rehydration.

The symptoms of heat cramp include:

  • high body temperature
  • dizziness
  • muscle pain or stiffness

Heat exhaustion requires medical attention if the symptoms last longer than an hour or worsen over time.

In addition to the symptoms of heat cramp, a person may experience:

  • vomiting
  • headaches
  • reduced concentration or impaired judgment

Heatstroke is very serious and requires medical attention at a hospital.

The symptoms of heatstroke include the symptoms of heat cramps, as well as:

  • seizures
  • difficulty maintaining consciousness
  • liver failure

Learn more about the difference between heat exhaustion and heatstroke here.

Exercising or moving more than usual

When a person moves, they create energy. Heat is the body’s way of releasing energy. But too much physical endurance can create too much body heat. To reduce body heat, a person can try temporarily moving less or only when necessary.

Perimenopause or menopause

During perimenopause and menopause, people often experience hot flashes and night sweats, which temporarily elevate body temperature.

Medications, hormones, and recreational drugs

Medications and other drugs can raise a person’s body temperature by affecting heat loss or production.

These include:

  • diuretics
  • anticholinergics
  • Beta-blockers
  • neuroleptic drugs
  • inhaled anesthetics
  • succinylcholine

These medications either impair the body’s ability to lose heat by sweating or decrease the body’s ability to get rid of excess heat.

Some medications, hormones, and recreational drugs can also cause the body to produce excess heat because they increase the metabolic rate. These include drugs like MDMA and cocaine.

Being unwell

Body temperature also increases in response to germs such as viruses and bacteria. An increased body temperature helps the body fight off invading illnesses, which is why a fever is often a sign of getting sick.

Thyroid storm

A thyroid storm is an excess of thyroid hormone in the body. It is a life threatening condition that requires immediate medical attention. A thyroid storm may occur after illness, surgery, infection, or pregnancy.

As well as a very high body temperature, symptoms of a thyroid storm include:

  • rapid heartbeat
  • sweating
  • nausea or vomiting
  • agitation
  • jaundice
  • abdominal pain

Malignant hyperthermia

Malignant hyperthermia is a genetic condition that causes a person to have a severe reaction to certain medications and drugs.

The symptoms include a rapid or irregular heartbeat, high body temperature, and severe muscle spasms. People with this condition require immediate medical attention.

Learn more about hyperthermia here.

Anyone with a body temperature of 103ºF (39.4ºC) or higher should immediately see their doctor.

Caregivers should take children under 3 months of age to the doctor if they have a rectal temperature of 100.4ºF (38ºC) or higher.

In children older than 3 months, a temperature of 102.2ºF (39ºC) or a fever that lasts longer than 24 hours requires medical attention.

People should visit a doctor if their body heat is higher than usual and they also have any of the following symptoms:

  • difficulty breathing
  • irritability, drowsiness, or weakness
  • a stiff neck
  • light sensitivity
  • vomiting
  • refusing to drink or becoming dehydrated
  • signs of rash or infection

The following are answers to additional questions about high body temperature.

Who is at risk of overheating?

Certain groups are more at risk of dying as a result of excessive outdoor heat. This includes older adults over 65, children, and people with heart or lung problems. People from historically marginalized groups who may have less access to means of cooling down are also more at risk, in particular non-Hispanic Black people.

How to reduce heat immediately?

This depends on the cause of the high temperature. A person can control a viral fever with medications such as ibuprofen (Advil). Other health-related causes may require other treatments. A person should see a doctor to find the underlying cause and get the best treatment. If the cause is excessive outdoor heat, a person should drink water, move to a shaded area, and avoid physical activity.

Which food reduces the body heat?

To help a person stay cool in hot weather, a person should eat fresh fruit and vegetables. Watermelons, cucumbers, and oranges are good choices as they contain a lot of water and can help a person stay hydrated. In addition, eating cool dairy products such as yogurt can help reduce body heat.

The body can reduce its temperature by sweating or releasing heat into surrounding cooler air or water.

However, in some cases, rising temperatures around the world and various health conditions and medications can make it challenging for a person to maintain normal body temperature.

A person can use a range of techniques to cool down. Not spending too much time in the sun, limiting movement, and wearing breathable fabrics can all be beneficial.

People should also stay hydrated to avoid dehydration, which further increases body temperature.