Chills But No Fever: What It Means & What To Do

November 2022

It is possible to experience chills, but to have your body temperature within a normal range. This may be popularly referred to as an “internal fever”, as your external body temperature is normal, however internally your body may feel warmer than usual and cause physical symptoms. 

You may have symptoms very similar to a fever (such as general malaise, chills and cold sweats), however the thermometer remains at 36 to 37°C, which is considered a normal range.

An “internal fever” is not an actual medical condition. Although you may indeed feel warm, it is just a colloquial way of expressing you have the same symptoms as a normal fever without a measurable rise in temperature.

Possible causes

Having chills without a fever can be caused by drastic changes to emotions (e.g. stress or anxiety) and can also occur during the ovulation phase of a woman's menstrual cycle.  It is also commonly felt after exercising or excessive physical exertion (e.g. carrying heavy bags or climbing a flight of stairs). After physical activity, body temperature usually returns to normal following a few minutes of rest.

At the onset of a cold or the flu, feeling unwell, feeling tired and overall heaviness are common, and the feeling of an “internal fever” can also emerge. Warm ginger tea is an excellent home remedy to aid in these specific symptoms.

Can chills but no fever be a sign of COVID-19?

An “internal fever” can happen when the body tries to fight off an infection, and can appear before a real fever emerges. It is possible that some people infected with COVID-19 may experience an “internal fever” before any other symptoms.

If you feel an “internal fever” coming on, you should monitor for any other new symptoms, especially those that are indicative of COVID-19 (e.g. a dry cough, excessive tiredness, loss of taste and smell, or fever).

What to do

If you experience chills and have a normal temperature, a warm bath, removing excess clothing and rest is advised. Oftentimes, the cause of this fever sensation is due to stress or an anxiety attack, both of which can also cause tremors throughout the body.

Taking antipyretics, such as acetaminophen or ibuprofen, is only recommended under medical advice and when you have a temperature of at least 38.5°C. With an “internal fever,” the thermometer does not show a rise in temperature, and therefore medication is generally not indicated.

If symptoms persist, however, you should see your doctor for a physical exam to find out what may be happening. In addition to blood and urine tests, your doctor may also order imaging tests (e.g. a chest x-ray to check for any lung changes that may be causing this sensation of a fever).

How to identify an "actual" fever

A fever is typically defined by a temperature exceeding 37.5 ºC. Other symptoms that can accompany a fever include:

  • Feeling hot
  • Cold sweats
  • Chills or shivers throughout the day
  • General malaise
  • Headache
  • Tiredness
  • Lack of energy

In cases of an “internal fever,” all of these symptoms may be present, however there is no measurable rise in temperature. Read more about how to identify a fever

What a fever means

A fever is a physiologic response employed by the body to fight off harmful microorganisms. By raising its temperature, the body can naturally protect and treat infections caused by viruses, fungi, bacteria or parasites. Therefore, a fever is not a disease, but rather just a symptom that is associated with many types of diseases and infections.

A fever is only really harmful when it exceeds 40 °C, but this can happen very quickly (especially in babies and children) and can cause seizures.

A mild fever is considered to be a temperature that rises up to 38°C and is typically not very serious. You may need to monitor your temperature and try to cool your body down to normal temperatures (around 36ºC) by taking off any excess clothing. With a fever above 38.5ºC, antipyretics (fever-lowering medication) may be indicated in conjunction with other natural methods to lower a high temperature.

The hypothalamus, also known as the body's thermostat, controls body temperature and is very sensitive to temperature changes. It can cause the body to produce more heat by signaling the muscles to tremor or "shiver" or send signals to your sweat glands to cool off. With a fever, the hypothalamus will set the body to a higher temperature to help combat infection.

When to go to the doctor

If you experience chills with no fever, you should see a doctor, especially if you have other symptoms such as:

  • Sneezing or coughing
  • Vomiting or diarrhea
  • Cold sores
  • Rapid temperature rises that exceed 39ºC
  • Fainting or decreased level of consciousness
  • Bleeding from the nose, anus or vagina with no apparent explanation

It is very important to discuss all the symptoms you have with your doctor, making sure to communicate when they first appeared, if you changed anything in your diet, or if you were recently in another country. If you are also experiencing pain, be sure to explain which part of the body is affected, when the pain started and if the intensity has been constant.

Having sufficient information can prompt your doctor to evaluate your condition thoroughly and indicate the most appropriate treatment.

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Edited by Tua Saude editing team in November 2022. Medical review completed by Dr. Clarisse Bezerra - Family Doctor in September 2019.

References

  • CENTERS FOR DISEASE CONTROL AND PREVENTION. Symptoms of COVID-19. 2021. Available on: <https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html>. Access in 21 Jun 2021
  • MEDLINE PLUS - U.S. NATIONAL LIBRARY OF MEDICINE. Chills. Available on: <https://medlineplus.gov/ency/article/003091.htm>. Access in 21 Jun 2021
Medical review:
Dr. Clarisse Bezerra
Family Doctor
Dr. Bezerra possesses a medical degree and specializes in family medicine. She is licensed to practice under CRM-CE licence #16976.