How to use a thermometer
There are 5 types of commonly available thermometers -- probe, ear canal, temporal artery, bulb, and liquid crystal medical indicators. The type you need depends on the age of the sick person. Where you place the thermometer when you take a temperature also depends on the age of the sick person.
Click on your child’s age to find out the type of thermometer to use, where to place it, whether you should use over-the-counter cold remedies, and what medicine is safe to use for fever. Antiviral medication is discussed elsewhere.
Probe
- Can be used to take oral, underarm (axillary), or rectal temperatures
- Hard to “break”
- Reading usually available in 5 - 30 seconds
- May eventually need button batteries replaced
- Disposable “covers” available, 30 - 50 for less than $5
- Often cost less than $10
Ear Canal
- Only for use in the ear canal
- Not recommended for use with babies under one
year of age. - Not accurate if there is earwax
- Reading usually available in 5 - 30 seconds
- Require AA or AAA batteries, may be provided with initial purchase
- Disposable “lens covers” available, 40 - 50 for $5 - $10
- Usually cost from $30 - $50
Temporal Artery
- Only for use on a person’s temple
- Not recommended for use with babies under one
year of age. - More accurate than ear canal and less accurate than rectal
- Reading usually available in 5 - 30 seconds
- Require AA, AA, or 9-volt batteries, may be provided with initial purchase
- Usually cost $30 - $50
Bulb
- Can be used to take oral, underarm (axillary), or rectal temperatures
- Made of glass
- CAUTION: Old-fashioned mercury thermometers are toxic if you break them. If you have one at home, ask your doctor or pharmacist if she can dispose of this for you
- New-style Galinstan or alcohol are safe for both you and the environment if you break them.
- Must be kept in place a few minutes to get an accurate reading
- Harder to read than other types of thermometer
- Must be “shaken” down after each use
- Don’t need a battery
- Usually cost $4 - $7
Liquid Crystal Medical Indicators
- Some can be used to take oral or underarm (axillary) temperatures. Others are used strictly under the arm
- Not recommended for use with babies under one
year of age. - NOTE: Older brands used on the forehead are not considered to be accurate
- Some new brands (NexTemp, TraxIt) appear to be accurate
- Must be kept in place a few minutes to get an accurate reading
- Most are single use
- Usually cost $10 - $15 for 100
Probe-style digital thermometers provide the best value for budget-conscious families. Buy one that says it can be used for oral, axillary (underarm), or rectal temperatures. Although you can clean them, it is good to have two in your home if you have a small child and need to take rectal temperatures. Mark the one you are using for rectal temperatures so you don’t put it into someone’s mouth. Rectal temperatures are naturally higher than oral or axillary (underarm) temperatures. When you tell a nurse or doctor how high a temperature is for a child, tell him whether it is oral, axillary, rectal, temporal artery, or ear canal. The following instructions are for probe-style digital thermometers.
Taking an oral temperature
- Many 4-5 year olds are old enough to have their temperature taken by mouth
- NOTE: If you child has had a hot or cold drink, wait at least 15 minutes before taking his temperature
- Wash the thermometer with lukewarm water and soap before using it. Then rinse it with cool water
- Put on a probe cover if you have one
- Turn the thermometer “on”
- Place the tip under your child’s tongue near his back molars
- The thermometer will beep when it is ready for you to read the temperature
Taking a rectal temperature
- Always use this method for infants under three months of age. It is also a good method to use for any child under three years of age
- Wash the thermometer with lukewarm water and soap before using it. Then rinse it with cool water
- Put on a probe cover if you have one
- Put a little bit of lubricant, such as petroleum jelly, on the end of the probe
- Turn the thermometer “on”
- Place your baby in one of two positions:
- Place her on her tummy. You may either put her on your lap or on a firm surface. Keep her in this position by placing one hand on her lower back just above her bottom
- Place him face up and bend his legs to his chest. Keep him in this position by placing one hand against the back of the thighs
- With your free hand
- Insert thermometer 1/2 inch to 1 inch into the anal opening
- CAUTION: Do not insert it any farther into the anal canal. Pushing the thermometer too far into the rectum could harm your baby
- Use two of your fingers to hold the thermometer in place while you cup you hand around your child’s bottom
- The thermometer will beep when it is ready for you to read the temperature
Taking an axillary (underarm) temperature
- Although not as accurate as a rectal temperature, it is OK to take an axillary temperature in a child older than 3 months.
- Wash the thermometer with lukewarm water and soap before using it. Then rinse it with cool water
- Turn the thermometer “on”
- Place the tip of the thermometer in your child's armpit
- Hold his arm tightly against his chest for about 1 minute
- The thermometer will beep when it is ready for you to read the temperature
Click on your child’s age to find out the type of thermometer to use, where to place it, whether you should use over-the-counter cold remedies, and what medicine is safe to use for fever. Antiviral medication is discussed elsewhere.
