When to use it
A rectal reading is recommended for babies 3 years of age and younger -- it provides the most accurate readings for that age group. Rectal readings are also recommended for older children who aren't able to have their temperature taken orally because of continual coughing or a too-congested nose.
How to do it
1. Read the directions that came with the thermometer so you'll know which beep (or series of beeps) is a sign that the thermometer is finished reading. Turn it on and check that the screen is clear of any previous readings.
2. Clean the tip of the thermometer with rubbing alcohol or soap and water. Then rinse it with cool water. If you have one available, cover the thermometer with a disposable single-use plastic sleeve.
3. Lubricate the tip of the thermometer with a water-soluble jelly.
4. Place your baby across your lap, face down. Don't forget to support his head. For an older child or a very squirmy baby, lay him down on a firm, flat surface (such as a changing table) or on top of a blanket on the floor.
5. Press the palm of one hand firmly against your baby's lower back to hold him still. With the other hand, turn on the thermometer switch and insert the thermometer about 1/2 inch into your baby's anus. Always stop if you feel resistance.
6. Hold the thermometer in place loosely with two fingers, keeping your hand cupped around your child's bottom, until you hear the beep.
7. Remove the thermometer to check the digital reading. Record the temperature and the time of day it was taken in case you need to inform the pediatrician.
8. If you used a disposable plastic sleeve, discard it right away. Clean the thermometer, replace it in its case, and mark the case "rectal" -- it's easy to grab an oral thermometer by accident if you're tired or it's dark in the room.