How Long Should a Fever Last? A Pediatrician Explains
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Most fevers caused by common viral illnesses last about 2 to 3 days.
Call your pediatrician if it lasts more than 24 hours in a child younger than 2 years. For a child age 2 or older, call if it lasts more than 3 days.
Call sooner if your child looks very sick, is getting worse or has other concerning symptoms.
- Many viral fevers last about 2 to 3 days.
- Age changes when you should call the pediatrician.
- Watch how your child looks and acts.
- Drinking, urination and breathing are important.
- A temperature that goes away and then returns deserves attention.
- A baby under 3 months with 100.4°F (38°C) or higher needs prompt medical care.
How Many Days Can a Viral Fever Last?
Many common viral illnesses cause a temperature for about 2 to 3 days. Some can last longer.
The number of days is only part of the story. Your child's age and symptoms matter too.
Pay attention to drinking, urination, breathing and alertness. Also watch whether your child is improving or getting worse.
Watch the child, not just the calendar.
A child who is drinking and interacting with you is more reassuring than one who is hard to wake, dehydrated or struggling to breathe.
When Has It Lasted Too Long?
The American Academy of Pediatrics gives parents useful age-based guidance.
Call your pediatrician if the temperature lasts more than 24 hours.
Call your pediatrician if it lasts more than 3 days (72 hours).
These are guidelines for calling your child's doctor. Do not wait for these time limits if your child looks very sick or is getting worse.
A baby younger than 3 months with a temperature of 100.4°F (38°C) or higher needs prompt medical evaluation.
Do not wait to see how long it lasts.
Why Can a Temperature Stay High for Several Days?
Viral infections are a common reason. Colds, influenza and other viruses can cause several days of illness.
Sometimes another cause needs to be considered. Examples include an ear infection, urinary tract infection, pneumonia or strep throat.
A longer illness does not automatically mean it is serious. It does mean that your pediatrician may want to reassess your child.
What If It Goes Away and Comes Back?
A temperature can rise and fall during an illness.
But call your pediatrician if your child seems to recover and then develops a new temperature, especially after being without one for more than 24 hours.
A returning temperature can sometimes signal a new infection or a complication. New or worsening symptoms make a call more important.
Does the Number Matter?
Yes, but it does not tell the whole story.
A child with a high temperature who is drinking and talking may look better than a child with a lower reading who is hard to wake.
Call your pediatrician if your child's temperature repeatedly rises above 104°F (40°C).
- Is your child drinking?
- Are they urinating regularly?
- Is their mouth very dry?
- Are they breathing comfortably?
- Are they alert and interacting with you?
- Are they getting better or worse?
- Have new symptoms appeared?
Do I Need to Treat Every Temperature?
No. Medicine is mainly used to help a child feel more comfortable. You do not need to make every reading normal.
Acetaminophen or ibuprofen may help when appropriate for your child's age. Use the correct product and dose for your child's weight.
Dr. G's QuickDose™ provides weight-based guidance for children's acetaminophen and ibuprofen.
Call if your child:
- Still looks sick when the temperature comes down
- Is getting worse instead of better
- Is not drinking well or shows signs of dehydration
- Has repeated vomiting or diarrhea
- Has severe ear pain, throat pain or another concerning symptom
- Has a new or unexplained rash
- Has a weakened immune system or important chronic condition
- Has temperatures repeatedly above 104°F (40°C)
Get urgent or emergency help if your child has:
- Serious trouble breathing
- Blue or gray lips or face
- Extreme sleepiness or is very hard to wake
- A stiff neck with a very ill appearance
- A seizure with concerning symptoms or poor recovery
- A sudden purple or bruise-like rash
- Severe dehydration or cannot keep fluids down
Call 911 if your child has a life-threatening emergency.
Frequently Asked Questions
Can a viral fever last 4 or 5 days?
Some viral illnesses can cause several days of elevated temperature. However, a child with symptoms lasting this long should be discussed with the pediatrician, especially if there is no clear improvement.
Is it normal for the temperature to come and go?
Yes. It can rise and fall during an illness. If it disappears for more than 24 hours and then returns, call your pediatrician.
What matters more: the number or how my child acts?
Both matter. But how your child looks, drinks, breathes and responds to you gives important information about how sick they may be.
The Bottom Line
Most viral fevers improve within about 2 to 3 days.
Call your pediatrician if symptoms last more than 24 hours in a child under age 2 or more than 3 days in a child age 2 or older.
Do not wait if your child looks very sick, is getting worse or has concerning symptoms.
A baby under 3 months with a temperature of 100.4°F (38°C) or higher needs prompt medical evaluation.
Related Fever Resources
Have another question about your child's temperature? Visit our Fever in Children Parent Guide.
References
- American Academy of Pediatrics, HealthyChildren.org. Fever Without Fear: Information for Parents
- American Academy of Pediatrics, HealthyChildren.org. Urgent Care, ER or Pediatrician? A Parent Guide
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