Temperature measurement

How the test is performed:

Several ways of measuring the body temperature are:

• Glass thermometer: first clean the thermometer with cool, soapy water or rubbing alcohol. Gripping the end opposite the bulb, shake the thermometer down until it reads 95 degrees F or less. You can measure the temperature on 3 body locations:
  • Oral: (In the mouth) Place the thermometer under the tongue and close the mouth using the lips to hold the thermometer tightly. The patient must breath through the nose. Leave the thermometer in the mouth for 3 minutes.
  • Rectal: For this method, use a rectal thermometer. This method is recommended for infants and small children who are not able to hold a thermometer safely in their mouths. Lubricate the bulb of the thermometer with a petroleum jelly. Place the small child face down on a flat surface or lap. Spread the buttocks and insert the bulb end of the thermometer about 1/2 to 1 inch into the anal canal. After 3 minutes, remove the thermometer and read.
  • Axillary: (in the armpit) This is the least accurate method. Place the thermometer in the armpit, with the arm pressed against the body for 5 minutes before reading.

• Read the thermometer by gripping the end opposite the bulb so that the numbers are facing you. Roll the thermometer back and forth between your fingers until you see a silver or red reflection in the column. Compare the end of the column with the degree marking in the lines on the thermometer.
• Plastic strip thermometer: The plastic strips contain a heat-sensitive liquid crystal which changes color to indicate the temperature. Put the strip on the forehead and read it after 1 minute. Read it while the strip is in place. This method is not very accurate.
• Electronic thermometer: You use this thermometer like a glass thermometer, but you read the temperature on a digital visual display.

How to prepare for the test:

It is recommended that the patient wait at least 1 hour after vigorous exercise or a hot bath. Wait for 20 to 30 minutes after smoking, eating, or drinking a hot or cold liquid.

How the test will feel:

There is very little discomfort.

Why the test is performed:

The measurement of the body temperature may be helpful in determining the presence or absence of fever. It may be helpful in monitoring to see if a treatment is working, especially in antibiotic treatment of infections.