Baby fever temperature

Baby fever temperature

According to American Academy of Pediatrics (AAP), a healthy body temperature of a baby is between 97.0F and 100.30F. When the rectal temperature of a baby reaches to 100.40F or higher, that is considered as fever. This is a very common symptom in babies and usually, fever doesn’t indicate anything serious. In most cases, fever does not require special medical care. However, high fever can cause certain difficulties for the baby and depend on the behavior, getting relevant medical attention is important.

Baby Temperature Chart

Baby’s temperature can be measured in several ways as oral (mouth), rectal (rectum), axillary (armpit) or tympanic (ear). Depending on the method, temperature reading varies. The rectal or tympanic temperature reading is a little bit higher than the oral reading where as an axillary temperature reading is little lower than the oral reading. However, the most suitable method for infants is to take the temperature rectally.

Given below is the comparison of temperatures in Fahrenheit and Celsius by the method.

Temperatures in FahrenheitTemperatures in Celsius
Axillary/Forehead (°F)Oral (°F)Armpit (Under Arm) (°F)Rectal/Ear (°F)Axillary/Forehead (°C)Oral (°C)Armpit (Under Arm) (°C)Rectal/Ear (°C)
98.4 – 99.399.5 – 99.998.4 – 99.2100.4 – 10136.9 – 37.437.5 – 37.737.5 – 37.638 – 38.3
99.4 – 101.1100 – 101.599.4 – 101101.1 – 102.437.5 – 38.437.8 – 38.537.8 – 38.438.4 – 39.1
101.2 – 102101.6 – 102.4101.2 – 102102.5 – 103.538.5 – 38.938.6 – 39.138.6 – 3939.2 – 39.7
102.1 – 103.1102.5 – 103.5102.1 – 103103.6 – 104.639 – 39.539.2 – 39.739.2 – 39.639.8 – 40.3
103.2 – 104103.6 – 104.6103.2 – 104104.7 – 105.639.6 – 4039.8 – 40.339.8 – 40.240.4 – 40.9


The following chart displays the normal range of temperature for babies.

MethodNormal temperature range
Rectal36.6°C to 38°C97.9°F to 100.3°F
Oral35.5°C to 37.5°C95.9°F to 99.5°F
Axillary36.5°C to 37.5°C97.8°F to 99.5°F
Tympanic35.8°C to 38°C96.4°F to 100.4°F
Armpit (Under Arm)36.5°C to 37.4°C97.5°F to 99.3°F


Keep in mind that degree of fever does not indicate the seriousness of the underlying illness. Always, pay more attention to the behavior of the baby to determine the recovery and seek further medical advice if you have any doubts.

How to Check Your Baby’s Temperature

The most appropriate method to take the temperature of the babies depends on their age. If the baby is younger than 2 years of age, rectal and axillary methods are the first and second choices subsequently. When the baby is between 2 to 5 years of age, the first choice is rectal and as the second choice, either axillary or tympanic method can be used.

Here are some of the tips that you could follow to make sure to obtain the correct reading.

Rectal Temperature

  • Keep the baby’s belly down across your lap.
  • Remember to clean the digital thermometer in lukewarm soapy water and rinse it well with cool water prior taking the temperature.
  • Coat the silver tip with moisturizing cream or petroleum jelly.
  • Inset the tip of the thermometer into the rectum for about 1 inch and hold it still until it beeps.
  • Remove the thermometer carefully and read the temperature.
  • Then, clean it with cool and soapy water or rub some alcohol.


Oral temperature

  • Clean the thermometer with cool, soapy water and rinse.
  • Place the tip of the thermometer under your baby’s tongue. (This method is not recommended for babies younger than 3 years of age)
  • Make sure your baby’s mouth is closed the whole time and remove the thermometer once it beeps.
  • Clean the thermometer with soapy water.


Axillary temperature

  • The axillary method is often used to take temperature in newborns and young children. Even if this doesn’t indicate fever and your baby still seems unwell, take a rectal measurement. You can either use a rectal or oral thermometer.
  • First, clean the thermometer with soapy water.
  • Place the top of the thermometer in your baby’s armpit.
  • Keep the baby’s arm still and pushed against the body.
  • Clean the thermometer.


Tympanic temperature

  • The tympanic method may provide low-temperature readings than the actual baby temperature. Even though it is easy to use, not a reliable technique as the rectal method.
  • Clean the probe tip prior to use.
  • Gently pull the top of the ear back and up to make a clear path inside the ear.
  • Gently insert the probe into the ear canal until it is fully sealed.
  • Hold down the thermometer tightly for one second.
  • Remove it and read the temperature.


Newborn Temperature

Newborns and infants who are under the age of 3 months have an undeveloped immune system. Therefore, fever is an important sign and can be the only symptom related to a serious illness. If you notice the baby’s temperature is slightly above the normal range (97F and 100.3F – rectal temperature), take your newborn to a doctor immediately.

Although, do not misinterpret the warmness of the baby with a fever. Sometimes, babies absorb the heat when they are being held for a while or being overdressed. It is best to take the temperature rectally or axillary. Normal newborn temperature is around 97.8F to 98.8F, when taken the axillary temperature. If the baby’s temperature exceeds this range, consider whether the baby is overdressed or was in outside for a while. Then, take the temperature once more to confirm the readings and if the baby continues to have a higher temperature, visit a doctor.

Healthy Resolution Group