When to Contact a Doctor for Persistent Fever
Call a doctor right away if your child:
- Is younger than 3-months old and has a rectal temperature of 100.4°F (38°C) or higher
- Is 3-12 months old and has a fever of 102.2°F (39°C) or higher
- Is under age 2 and has a fever that lasts longer than 24-48 hours
- Is older and has a fever for longer than 48-72 hours
- Has a fever over 105°F (40.5°C), unless it comes down readily with treatment and the person is comfortable
- Has other symptoms that suggest an illness may need to be treated, such as a sore throat, earache, or cough
- Has been having fevers come and go for up to a week or more, even if they are not very high
- Has a serious medical illness, such as a heart problem, sickle cell anemia, diabetes, or cystic fibrosis
- Recently had an immunization
- Has a new rash or bruises appear
- Has pain with urination
- Has trouble with the immune system (chronic steroid therapy, after a bone marrow or organ transplant, spleen was removed, is HIV-positive, or is being treated for cancer)
- Has recently traveled to a third world country
Call 911 if you or your child has a fever and:
- Is crying and cannot be calmed down (children)
- Cannot be awakened easily or at all
- Seems confused
- Cannot walk
- Has difficulty breathing, even after their nose is cleared
- Has blue lips, tongue, or nails
- Has a very bad headache
- Has a stiff neck
- Refuses to move an arm or leg (children)
- Has a seizure
Call your doctor right away if you are an adult and you:
- Have a fever over 105°F (40.5°C), unless it comes down readily with treatment and you are comfortable
- Have a fever that stays at or keeps rising above 103°F
- Have a fever for longer than 48-72 hours
- Have had fevers come and go for up to a week or more, even if they are not very high
- Have a serious medical illness, such as a heart problem, sickle cell anemia, diabetes, cystic fibrosis, COPD, or other chronic lung problems
- Have a new rash or bruises appear
- Have pain with urination
- Have trouble with your immune system (chronic steroid therapy, after a bone marrow or organ transplant, had spleen removed, HIV-positive, were being treated for cancer)
- Have recently traveled to a third world country
What to Expect at Your Office Visit
Your doctor will perform a physical examination, which may include a detailed examination of the skin, eyes, ears, nose, throat, neck, chest, and abdomen to look for the cause of the fever.
Treatment depends on the duration and cause of the fever, as well as your other symptoms.
The following tests may be performed:
- Blood studies, such as a CBC or blood differential
- X-ray of the chest
Fever and Taking your Child's Temperature
You've probably experienced waking in the middle of the night to find your child flushed, hot, and sweaty. Your little one's forehead feels warm. You immediately suspect a fever, but are unsure of what to do next. Should you get out the thermometer? Call the doctor?
In healthy kids, fevers usually don't indicate anything serious. Although it can be frightening when your child's temperature rises, fever itself causes no harm and can actually be a good thing — it's often the body's way of fighting infections. And not all fevers need to be treated. High fever, however, can make a child uncomfortable and worsen problems such as dehydration.
Here's more about fevers, how to measure and treat them, and when to call your doctor.
Fever occurs when the body's internal "thermostat" raises the body temperature above its normal level. This thermostat is found in the part of the brain called the hypothalamus. The hypothalamus knows what temperature your body should be (usually around 98.6° Fahrenheit or 37° Celsius) and will send messages to your body to keep it that way.
Most people's body temperatures even change a little bit during the course of the day: It's usually a little lower in the morning and a little higher in the evening and can fluctuate as kids run around, play, and exercise.
Sometimes, though, the hypothalamus will "reset" the body to a higher temperature in response to an infection, illness, or some other cause. So, why does the hypothalamus tell the body to change to a new temperature? Researchers believe turning up the bodies heat is the body's way of fighting germs that causing infections and making the body a less hospitable place for them to reside.