Fever is a body temperature of more than 100.5° F (when taken by mouth) that lasts for a day or more. Fever is usually caused by an infection. Infections can be viral (in which case the symptoms can be treated even though there may be no treatment for the cause), or they can be bacterial or fungal (in which case medicines may be prescribed after the infection is diagnosed). Other causes of fever include inflammatory illness, drug reactions, or tumor growth. Sometimes, the cause may not be known. In an infection, the fever is a result of the body "heating up" to try to kill any invading germs. A fever is an important natural defense against germs.

People getting chemo are more likely to have infections because they have lower numbers of the white blood cells needed to fight them (see the section on blood counts). It is good to have an easy-to-read, easy-to-use, oral thermometer (one made to take your temperature by mouth) so you can check your temperature to see if you have a fever.

What to look for

• Increased skin temperature
• Feeling warm
• Feeling tired
• Headache
• Feeling cold
• Shaking chills
• Body aches
• Skin rashes
• Any new area of redness or swelling
• Pus or yellowish discharge from an injury or other location
• New cough or shortness of breath
• New abdominal pain
• Burning or pain when urinating
• Sore throat
• The patient is confused, doesn't know where he is, becomes forgetful, or isn't making sense (See the section on confusion.)

What the patient can do

• If you start feeling warm or cold, check your temperature by mouth every 2 to 3 hours. If you are unable to hold the thermometer in your mouth, put it under your armpit.
• Keep a record of temperature readings.
• Drink a lot of liquids (such as water, fruit juices, cola, Popsicles^®, and soups).
• Get enough rest.
• Cover yourself with a blanket if you get chilly.
• Cover yourself only with a sheet if you feel hot.
• Use a cold compress on your forehead if you feel hot.
• Take acetaminophen (Tylenol^®) or other medicines for fever only if your doctor tells you to do so.

What caregivers can do

• Watch for shaking chills, and check the patient's temperature after the shaking stops.
• Check the patient's temperature by placing the thermometer in mouth or under his armpit. (Do not take the temperature rectally unless the doctor tells you it's OK.)
• Encourage visitors who have fevers or the flu to visit the patient by phone until they are well again.
• Offer extra fluids and snacks.
• Help the patient take medicines on schedule.
• Call the doctor if the patient is confused, doesn't know where he is, becomes forgetful, or isn't making sense (See the section on confusion.)

Call the doctor if the patient:

• Has a temperature of 100.5° F or higher when taken by mouth
• Has 2 or more of the symptoms listed under the "What to look for" section above
• Has a fever lasting for more than 24 hours
• Has shaking chills
• Cannot take fluids

Go back to Caring for the Patient with Cancer at Home: A Guide for Patients and Families.

Last Medical Review: 04/27/2009
Last Revised: 04/27/2009