Use a digital thermometer
to check your child’s temperature. Don’t use a mercury thermometer. There are
different kinds and uses of digital thermometers. They include:
Rectal. For children younger than 3
years, a rectal temperature is the most accurate.
Forehead (temporal). This works for
children age 3 months and older. If a child under 3 months old has signs of illness,
this can be used for a first pass. The provider may want to confirm with a rectal
Ear (tympanic). Ear temperatures are
accurate after 6 months of age, but not before.
Armpit (axillary). This is the least
reliable but may be used for a first pass to check a child of any age with signs of
illness. The provider may want to confirm with a rectal temperature.
Mouth (oral). Don’t use a
thermometer in your child’s mouth until he or she is at least 4 years old.
Use the rectal thermometer with care. Follow the product maker’s
directions for correct use. Insert it gently. Label it and make sure it’s not used
the mouth. It may pass on germs from the stool. If you don’t feel OK using a rectal
thermometer, ask the healthcare provider what type to use instead. When you talk with
any healthcare provider about your child’s fever, tell him or her which type you used.
Below are guidelines to know if your young child has a fever. Your
child’s healthcare provider may give you different numbers for your child. Follow
provider’s specific instructions.
Fever readings for a baby under 3 months old:
- First, ask your child’s healthcare provider how you should take
- Rectal or forehead: 100.4°F (38°C) or higher
- Armpit: 99°F (37.2°C) or higher
Fever readings for a child age 3 months to 36
months (3 years):
- Rectal, forehead, or ear: 102°F (38.9°C) or higher
- Armpit: 101°F (38.3°C) or higher
Call the healthcare provider in these
- Repeated temperature of 104°F (40°C) or higher in a child of any
- Fever of 100.4° F (38° C) or higher in baby younger than 3
- Fever that lasts more than 24 hours in a child under age 2
- Fever that lasts for 3 days in a child age 2 or older