Overview | Possible Causes | Care and Treatment | When to Call the Doctor

What is a fever?

A fever is a higher-than-normal body temperature and is a part of our body's natural response to infection. The average normal body temperature is 98.6 degrees Fahrenheit. When your body's temperature rises a few degrees above normal, it is a sign that your body is fighting infection and is generally not cause for concern. In these cases, a fever is the response you want your body to have since it means that it is healthy enough to fight infection. For this reason it is not always a good idea to try and bring a fever down too quickly. However, a fever that goes above 102 degrees Fahrenheit is a cause for concern, and treatment should be initiated.

Aside from an elevated temperature, chills, and aches, a lack of energy and a flush complexion are common symptoms experienced by people with a fever.

Possible Causes

What causes a fever?

A fever has many causes and can be a symptom of almost any illness. Among the most common are:

However, if you or your loved are experiencing a higher-than-normal body temperature and no other symptoms of illness, do not assume something is wrong. A person's body temperature changes throughout the day and varies with many normal activities and emotions. For example, stress, excitement, wearing extra clothing, food, certain medications, a woman's menstrual cycle and exercise can all raise body temperature. Also, children tend to have a slightly higher body temperature than adults.

Care and Treatment

What is the best way to measure body temperature?

The best way to measure body temperature is using a thermometer inserted orally, rectally, axillary (under the arm), or by using a special instrument commonly sold in stores that is inserted in the ear and measures the temperature of the eardrum.

Can a fever be treated at home?

If your fever is mild (less than 101 degrees), then no medical treatment is required. Simply make sure that you drink plenty of fluids no alcohol – and get plenty of rest. For higher temperatures, there are many effective approaches to getting your fever under control. The most common approaches include medications such as aspirin, acetaminophen, and ibuprofen. If you have a child under age 17 who has a fever, DO NOT give the child aspirin. Aspirin in children may cause Reye's syndrome, a sometime fatal illness. Taking a lukewarm bath (around 98 degrees) may also help bring the body's temperature down.

When to Call the Doctor

When is a fever cause for concern?

If any of the following situations apply, call a doctor as soon as possible:

  • A fever is accompanied by a stiff neck, confusion or irritability.
  • Any time a child under 6 months has a fever.
  • Whenever a child between the ages of 6 months and a year has a fever that lasts beyond 24 hours.
  • A fever remains above 103 degrees longer than 2 hours after home treatment.
  • A fever lasting longer than 2 days.

Any fever in an adult that goes above 105 degrees Fahrenheit and does not come down with treatment is a life-threatening medical emergency and 9-1-1 should be called.


  • Hague R. Managing the child with a fever. Practitioner. 2015;259(1784):17-21, 2-3.
  • Tess AV. Chapter 8. Fever. In: Henderson MC, Tierney LM, Jr., Smetana GW. eds. The Patient History: An Evidence-Based Approach to Differential Diagnosis. New York, NY: McGraw-Hill; 2012.
  • NHS Choices. Fever in children. Accessed 2/24/2016.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition. This document was last reviewed on: 04/22/2014