Aches, Pain, Fever (cont.)

Medical Author:
Medical Editor:

How should I take a temperature for fever?

Digital thermometers can be used to measure rectal, oral, or axillary (under the armpit) temperatures. The American Academy of Pediatrics does not recommend use of mercury thermometers (glass), and they encourage parents to remove mercury thermometers from their households to prevent accidental exposure to this toxin.

Measuring an axillary (under the armpit) temperature for fever

Axillary temperatures are not as accurate as rectal or oral measurements, and these generally measure 1 degree lower than a simultaneously obtained oral temperature.

  • Place the tip of the digital thermometer in your child's armpit.
  • Leave in place about one minute or until you hear a beep to check a digital reading.

Measuring fever by eardrum temperature

Tympanic (ear) thermometers must be placed correctly in your child's ear to be accurate. Too much earwax can cause the reading to be incorrect.

Eardrum temperature measurements are not accurate in small children and should not be used in children under 3 years (36 months) of age. This is especially true in infants below 3 months of age when obtaining an accurate temperature is very important.

Measuring fever by oral temperature

People 4 years old and older can have their temperature taken with a digital thermometer under the tongue with their mouth closed.

  • Clean the thermometer with soapy water or rubbing alcohol and rinse.
  • Turn the thermometer on and place the tip of the thermometer as far back under the tongue as possible.
  • The mouth should remain closed, as an open mouth can cause readings to be inaccurate.
  • The thermometer should remain in place for about one minute or until you hear the beep. Check the digital reading.

Avoid hot or cold drinks within 15 minutes of oral temperature measurement to ensure correct readings.

Measuring fever by rectal temperature

The American Academy of Pediatrics recommends rectal temperature measurements for children under 3 years of age, as this gives the most accurate reading of core temperature.

  • Clean the thermometer with soapy water or rubbing alcohol and rinse with cool water.
  • Use a small amount of lubricant, such as petroleum jelly, on the end.
  • Place the child or baby prone (belly-side down) on a firm surface, or place your child face up and bend his legs to his chest.
  • After separating the buttocks, insert the thermometer approximately ½ to 1 inch into the rectum. Do not insert it too far.
  • Hold the thermometer in place, loosely keeping your hand cupped around your child's bottom, and keep your fingers on the thermometer to avoid it accidently sliding further into the rectum. Keep it there for about one minute, until you hear the beep.
  • Remove the thermometer, and check the digital reading.
  • Label the rectal thermometer so it's not accidentally used in the mouth.

A rectal temperature will read approximately 1 degree higher than a simultaneously obtained oral temperature.

Medically Reviewed by a Doctor on 6/27/2014

Patient Comments

Viewers share their comments

Fever - Treatments Question: What treatments helped to reduce your fever?
Fever - Signs and Symptoms Question: What signs and symptoms did you or your child experience along with a fever?
Fever - Complications Question: Did you or your child experience any complications when you had fever? If so, what were they?

STAY INFORMED

Get the Latest health and medical information delivered direct to your inbox!