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:
children younger than 3 years, a rectal temperature is the most accurate.
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 temperature.
Ear temperatures are accurate after 6 months of age, but not before.
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.
Don’t use a thermometer in your child’s mouth until he or she is at least 4 years
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 cases:
- Repeated temperature of 104°F (40°C) or higher in a child of any
- Fever of 100.4° (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