Fever (0-12 Months) – Seattle Children’s

Is this your child’s symptom?

• An abnormal high body temperature
• Fever is the only symptom˳ Your child has a true fever if:
• Rectal (bottom), Ear or Forehead temperature: 100˳4° F (38˳0° C) or higher
• Under the arm (armpit) temperature: 99° F (37˳2° C) or higher
• Caution: Ear temperatures are not accurate before 6 months of age
• Caution: Forehead temperatures must be digital˳ Forehead strips are not accurate˳

Causes of Fever

• Overview˳ Almost all fevers are caused by a new infection˳ Viruses cause 10 times more infections than bacteria˳ The number of germs that cause an infection are in the hundreds˳ Only a few common ones will be listed˳
• Viral Infections˳ Colds, flu and other viral infections are the most common cause˳ Fever may be the only symptom for the first 24 hours˳ The start of viral symptoms (runny nose, cough, loose stools) is often delayed˳ Roseola is the most extreme example˳ Fever may be the only symptom for 3 to 5 days˳ Then a rash appears˳
• Bacterial Infections˳ A bladder infection is the most common cause of silent fever in girls˳
• Vaccine Fever˳ Fever with most vaccines begins within 12 hours˳ It lasts 2 to 3 days˳ This is normal and harmless˳ It means the vaccine is working˳
• Newborn Fever (Serious)˳ Fever that occurs during the first 3 months of life can be serious˳ All of these babies need to be seen as soon as possible˳ The fever may be due to sepsis (a bloodstream infection)˳ Bacterial infections in this age group can get worse quickly˳ They need rapid treatment˳
• Meningitis (Very Serious)˳ A bacterial infection of the membrane that covers the spinal cord and brain˳ The main symptoms are a stiff neck, headache and confusion˳ Younger children are lethargic or so irritable that they can’t be consoled˳ If not treated early, can suffer brain damage˳
• Overheated˳ The fever is usually low grade˳ Can occur during heat waves or from being overdressed˳ The temp becomes normal in a few hours after moving to a cooler place˳ Fever goes away quickly with rest and drinking extra fluids˳
• Not Due to Teething˳ Research shows that “getting teeth” does not cause fevers˳

Fever and Crying

• Fever on its own shouldn’t cause much crying˳
• Frequent crying in a child with fever is caused by pain until proven otherwise˳
• Hidden causes can be ear infections, kidney infections, sore throats and meningitis˳

Normal Temperature Range

• Rectal˳ A reading of 98˳6° F (37° C) is just the average rectal temp˳ A normal low can be 96˳8° F (36° C) in the morning˳ It can change to a high of 100˳3° F (37˳9° C) late in the day˳ This is a normal range˳

When to Call for Fever (0-12 Months)

Call 911 Now

• Not moving
• Can’t wake up
• Severe trouble breathing (struggling for each breath; can barely speak or cry)
• Purple or blood-colored spots or dots on skin
• You think your child has a life-threatening emergency

Call Doctor or Seek Care Now

• Trouble breathing, but not severe
• Great trouble swallowing fluids or spit
• Fever in baby less than 12 weeks old˳ Caution: Do NOT give your baby any fever medicine before being seen˳
• Fever over 104° F (40° C)
• Shaking chills (shivering) lasting more than 30 minutes
• Nonstop crying or cries when touched or moved
• Won’t move an arm or leg normally
• Dehydration suspected˳ No urine in over 8 hours, dark urine, very dry mouth and no tears˳
• Weak immune system˳ Examples are sickle cell disease, HIV, cancer, organ transplant, taking oral steroids˳
• Your child looks or acts very sick
• You think your child needs to be seen, and the problem is urgent

Contact Doctor Within 24 Hours

• Age 3-6 months old with fever
• Age 6-12 months old with fever that lasts more than 24 hours˳ There are no other symptoms (such as cough or diarrhea)˳
• Fever lasts more than 3 days
• Fever returns after gone for more than 24 hours
• You think your child needs to be seen, but the problem is not urgent

Contact Doctor During Office Hours

• You have other questions or concerns

Self Care at Home

• Fever with no other symptoms and your child acts mildly ill

Care Advice for Fever

1. What You Should Know About Fever:
   • Having a fever means your child has a new infection˳
   • It’s most likely caused by a virus˳
   • You may not know the cause of the fever until other symptoms develop˳ This may take 24 hours˳
   • For infants more than 3 months old, most fevers are good for sick children˳ They help the body fight infection˳
   • Use the ranges below to help put your child’s level of fever into perspective:
   • 100° – 102° F (37˳8° – 39° C) Low grade fever: helpful, good range˳ Don’t treat˳
   • 102° – 104° F (39 – 40° C) Average fever: helpful˳ Treat if causes discomfort˳
   • Over 104° F (40° C) High fever: causes discomfort, but harmless˳ Always treat˳
   • Over 106° F (41˳1° C) Very high fever: important to bring it down˳ Rare to go this high˳
   • Over 108° F (42˳3° C) Dangerous fever: fever itself can be harmful˳
2. Treatment for All Fevers – Extra Fluids:
   • Fluids alone can lower the fever˳ Reason: being well hydrated helps the body give off heat through the skin˳
   • For shivering (or the chills), give your child a blanket˳ Make them comfortable˳
   • Offer your child extra water or other fluids by mouth˳ Cold fluids are better˳ Until 6 months old, only give extra formula or breastmilk˳
   • For all children, dress in 1 layer of light weight clothing, unless shivering˳ Reason: also helps heat loss from the skin˳
   • For shivering (or the chills), give your child a blanket˳ Make them comfortable˳
   • Caution: if a baby under 1 year has a fever, never overdress or bundle up˳ Reason: Babies can get over-heated more easily than older children˳
3. Fever Medicine:
   • Caution: Do not give a baby under 3 months any fever medicine˳ Most of these babies will need to be seen˳
   • For fevers 100°-102° F (37˳8° – 39°C), fever meds are not needed˳ Reason: fevers in this range help the body fight the infection˳ Fevers turn on the body’s imune system˳ Fevers don’t cause any discomfort˳Fever meds are mainly needed for fevers higher than 102° F (39° C)˳
4. Give an acetaminophen product (such as Tylenol)˳
5. Another choice is an ibuprofen product (such as Advil) if over 6 months old˳
6. Goal of treatment: keep the fever at a helpful level˳ Most often, the fever meds lower the fever by 2° to 3° F (1 – 1˳5° C)˳ They do not bring it down to normal˳ It takes 1 or 2 hours to see the effect˳
7. Do not use aspirin˳ Reason: Risk of Reye syndrome, a rare but serious brain disease˳
8. Do not use both acetaminophen and ibuprofen together˳ Reason: Not needed and a risk of giving too much˳
9. Pain: fever does not cause pain˳ If your child also has pain, it’s from the infection˳ It may be a sore throat or muscle pain˳ Treat the pain, if it’s more than mild˳
10. Return to Child Care:
    • Your child can return to child care after the fever is gone˳ Your child should feel well enough to join in normal activities˳
11. What to Expect:
    • Most fevers with viral illnesses range between 101° and 104° F (38˳4° and 40° C)˳
    • They may last for 2 or 3 days˳
    • They are not harmful˳
12. Call Your Doctor If:
    • Your child looks or acts very sick
    • Any serious symptoms occur such as trouble breathing
    • Fever goes above 104° F (40° C)
    • Any fever occurs if less than 12 weeks old
    • Fever without other symptoms lasts more than 24 hours
    • Fever lasts more than 3 days (72 hours)
    • You think your child needs to be seen
    • Your child becomes worse

And remember, contact your doctor if your child develops any of the ‘Call Your Doctor’ symptoms˳

Disclaimer: this health information is for educational purposes only˳ You, the reader, assume full responsibility for how you choose to use it˳

Last Reviewed: 03/27/2023

Last Revised: 12/30/2022

Copyright 2000-2023 Schmitt Pediatric Guidelines LLC˳