Taking Your Child's Temperature

A medically significant fever is a temperature over 100.4°F (38°C).

  • Use a thermometer. Feeling your child’s body or forehead is not reliable.
  • 0–3 months: Rectal temperature is most accurate.
  • Over 3 months: Armpit, ear, and forehead temperatures are convenient but less accurate than rectal or oral temperatures.
  • 4 years and older: Oral (mouth) temperatures may be reliable with cooperative children. Ear and forehead temperatures are still acceptable.

Fever Reducers

Please give a fever reducer to a child over 3 months who has a fever and is uncomfortable or not drinking/feeding well. We will be able to assess your child better in the office if their fever is reduced at the time of any appointment.

  • Acetaminophen (Tylenol): May be used at any age.
  • Ibuprofen (Advil, Motrin): May be used only at 6 months or older.
  • Never give aspirin to anyone under 18 years old because of the risk of Reye syndrome.
  • Do not use rubbing alcohol to reduce fever; it can be absorbed and cause toxic effects.

When to Seek Care for Fever

INFANTS UNDER 2 MONTHS

  • GO TO THE EMERGENCY ROOM if your baby's rectal temperature is 100.4°F (38.0°C) or higher.
  • Pediatric services are available at Newton Wellesley Hospital and Boston Children's Hospital – Boston location only.

INFANTS 2–6 MONTHS

  • SCHEDULE AN APPOINTMENT if your child has a fever over 100.4°F (38°C), is acting sick, is not drinking well, Is not having a wet diaper at least every 6 hours, or you would like them to be evaluated

CHILDREN 6 MONTHS–3 YEARS

Schedule an Appointment if Your Child Has a Fever and Any of the Following Apply:

  • It is influenza season or your child has recently been exposed to influenza (“the flu”).
  • Your child’s temperature is 102°F (39°C) or higher.
  • Your child has a fever over 100.4°F (38°C) with other symptoms, such as cough, diarrhea, or rash.
  • Fever lasts more than 48 hours.
  • Child is not drinking well or is not having a wet diaper at least every 6 hours.
  • Child is acting sick.
  • Fever stopped and then returned.
  • You would like your child to be seen.

You may monitor the fever at home for 24–48 hours if the temperature is less than 102°F (39°C), decreases with treatment, your child's behavior improves when the temperature comes down, and your child is breathing, eating, sleeping, and acting well.

CHILDREN OVER 3 YEARS

  • A fever may be watched at home for 24–48 hours if it decreases with treatment and your child's behavior improves when the temperature comes down. If your child is breathing, eating, sleeping, and acting well, they are less likely to have a serious illness.
  • SCHEDULE AN APPOINTMENT OR CONSIDER A HOME INFLUENZA TEST if it is influenza season or your child has recently been exposed to influenza (“the flu”).
  • SCHEDULE AN APPOINTMENT IF fevers are lasting longer than 48 hours, child has fevers in addition to other symptoms (such as cough, diarrhea or rash), child is not drinking well and urinating normally, stopped having fevers and now fevers have returned , or you would like your child seen.

Schedule an Immediate Appointment at Any Age If:

  • Fever lasts 3–5 days or more
  • Temperature is 104–105°F (40–40.6°C)
  • Child seems very sick or very fussy
  • Child is too sleepy
  • Your child seems dehydrated or is not drinking well. Signs of dehydration may include not urinating at least every 6 hours, dark urine, a dry mouth, or no tears when crying.
  • Child has an underlying medical condition, such as immunocompromise, heart disease, cancer, or seizure disorder.
  • Child has not received all recommended childhood vaccines

Go to the Emergency Room If:

  • Child is too weak or sleepy to move around on their own
  • Child is struggling to breathe
  • Child cannot stop crying, even after a fever reducer
  • Child is in significant pain
  • Child has a stiff neck or seizure
  • Temperature is 106°F (41.1°C) or higher
  • Child appears to be having a life-threatening emergency

How to Help Your Sick Child

HYDRATION

  • Encourage plenty of fluids, including water and pediatric electrolyte-containing fluids such as Pedialyte.
  • Infants under 6 months: Give only breast milk or formula; do not give water.

CLOTHING

  • Keep the room comfortably cool and dress your child in light clothing.
  • If your child is shivering, you may give them a blanket.
  • Never overdress or bundle a baby under 1 year old, as babies can easily overheat.

Return to School & Activities

Your child may return to school and regular activities when they are feeling better and have had no fever over 100.4°F (38°C) for 24 hours without fever-reducing medication.