
A Thermometer is an Essential Item for Baby Healthcare. However, many parents still don’t know how to use a thermometer correctly and how to read the results accurately. Let’s find out with AVAKids in the article below!
Common Types of Thermometers
Currently, there are 3 commonly used types of thermometers:
Mercury Thermometers
The mercury thermometer was invented in 1714 by Daniel Gabriel Fahrenheit and is still widely used today. This thermometer consists of 3 parts: the temperature sensing part, the stem, and the display part. It works based on the expansion of mercury.
Advantages:
- Highly accurate results.
- The cheapest among thermometer types.
Disadvantages:
- Quite dangerous if the thermometer breaks because mercury is very toxic.
- Takes a long time to get results.

Mercury Thermometer
Digital Thermometers
Digital thermometers are very popular nowadays due to their accuracy and fast measurement speed. The device uses infrared radiation sensing technology to measure temperature. Operation is very simple, suitable for all users.
Advantages:
- Can be used for both children and adults.
- High safety.
- Easy to use.
Disadvantages:
- Results are less accurate compared to other types.

Digital Thermometer
Infrared Thermometers
Infrared thermometers can measure temperature on the forehead, ear, or both forehead and ear based on the principle of measuring the amount of infrared radiation emitted by the body without touching the person or object being measured. In addition, infrared thermometers are also widely used in industry.
Advantages:
- Fast measurement time, within seconds.
- Can be used for all subjects, even children 6 months old.
- Absolute safety because there is no need to contact the body during measurement.
Disadvantages:
- High cost.

Infrared Thermometer Gluck Care FC-IR100
The Importance of Measuring Body Temperature and Body Temperature Indicators
The Importance of Temperature Measurement
A thermometer is an indispensable medical device in every family, saving both cost and time. With a thermometer, you can quickly and easily know your body temperature for the fastest and best treatment, especially for families with children.
Classification of Body Temperature
There are 3 main types of body temperature:
Normal Temperature: The average normal body temperature is 37 degrees Celsius, measured orally. However, this temperature can fluctuate higher or lower depending on activity and time of day.
Fever:
- For infants under 3 months old, a fever is a rectal temperature of 38 degrees Celsius or an axillary temperature of 37.3 degrees Celsius.
- In children, a fever is a rectal temperature of 38 degrees Celsius or an axillary temperature of 37.6 degrees Celsius.
- In normal adults, a fever is an oral or axillary temperature of 37.6 degrees Celsius, or a rectal or ear temperature of 38.1 degrees Celsius.
Hypothermia: Low body temperature is common in cold weather, or due to the use of stimulants, emotional shock, or underlying medical conditions such as diabetes or thyroid problems. When experiencing hypothermia, you will feel cold, shivering, and have difficulty breathing,…
Hypothermia is very common in infants and young children. Some common causes include:
- Due to environmental factors such as: Weather, unprotected body contact with cold water,…
- Wearing damp clothing, soaking in cold water for too long,…
- The mother giving birth in an environment with a temperature lower than recommended.
- The mother giving birth by cesarean section or having hypertension.

Body temperature reflects health status
Instructions on How to Measure and Read a Mercury Thermometer Accurately
To ensure safety and avoid infection before use, you should clean the thermometer with a cotton ball soaked in alcohol, wiping the tip of the thermometer – the area that comes into contact with the body during measurement.
How to Use a Mercury Thermometer
- Step 1: Before measuring temperature, hold the end of the thermometer firmly and shake it vigorously towards the measuring tip so that the temperature drops below 35 degrees Celsius.
- Step 2: Place the mercury thermometer in the measurement location and hold it there for at least 5-7 minutes.
- Step 3: Remove the thermometer and read the result displayed on it.
- Step 4: After use, shake the thermometer to bring the mercury column back to the lowest level, clean and store the thermometer in a cool and safe place. If rectal measurement is needed, it is recommended to purchase a separate thermometer for other areas to minimize the risk of infection.
Best Placement Locations for Accurate Readings
- Rectally: This is the most accurate way to measure body temperature and can be used for infants, young children, and those who cannot safely hold a thermometer in their mouth.

Rectal temperature measurement is the most accurate method
- Under the tongue (Orally): This is a common method for accurate readings and can be used for children 5 years and older. For the most accurate results, breathe through your nose and place the thermometer under the tongue to one side. Results are typically 0.3-0.8 degrees Celsius lower than rectal readings.

Oral thermometer measurement is quite simple
- Under the arm (Axillary): This is the simplest method of taking temperature, just clip the mercury thermometer under the arm. However, axillary temperature readings can be 0.5-1.5 degrees Celsius lower than rectal readings.

Axillary temperature measurement is quite safe for children and the elderly
How to Read a Mercury Thermometer
The holding time for the thermometer varies depending on the area being measured. Accordingly, you need to hold the thermometer for about 2-3 minutes for rectal measurements, about 3-5 minutes for axillary or oral measurements. When removing the thermometer to read the result, avoid shaking the instrument as this will affect the reading.
To get the most accurate reading, first hold the thermometer horizontally, then raise it to eye level. Each graduation mark corresponds to 0.1 degrees Celsius, and the measured result is the number closest to the end of the mercury column.

The measurement result is the end of the mercury column
What to Do if a Mercury Thermometer Breaks
- When a mercury thermometer breaks, it easily releases mercury into the air. Therefore, do not clean up broken mercury with a vacuum cleaner.
- Turn off all air conditioners and fans to minimize mercury vaporization.
- Wear gloves when cleaning up mercury.
- To limit the spread of mercury, do not use a broom to sweep it up. Sprinkle sulfur powder on the broken mercury to limit evaporation before sweeping it up.
- The best way is to use a cotton ball soaked in water to collect the mercury beads into a glass jar and seal it tightly.
- Never pour broken mercury thermometer pieces down the drain. Mercury is very toxic and can damage plumbing systems and contaminate water sources.
- After cleaning up a broken mercury thermometer, change your clothes and wash your hands thoroughly with hand soap.
- If broken mercury thermometer pieces get on clothing, separate them from other clothes to prevent further contamination. Also, avoid stepping on or touching mercury with cloth, as this will spread it further.
- If any signs of mercury poisoning appear, take the person to the nearest medical facility for diagnosis and prompt treatment.

Use Lifebuoy Moisturizing Hand Wash, Mild Scent, 444 ml after cleaning up a broken thermometer