Over the course of my career as a family physician, I have witnessed the evolution of various thermometric tools, from traditional mercury thermometers to modern electronic thermometers. The most impressive change is the gradual elimination of mercury thermometers from the market. Many patients ask me if the mercury thermometer was made obsolete because it was not accurate, and today, I'm going to solve this puzzle.
One spring three years ago, Xiao Ming, a lively eight-year-old boy, was rushed to my clinic with a fever. Worriedly, his mother pulled a mercury thermometer out of her bag, a family necessity for her for years. Xiao Ming's body temperature showed 38.7°C, and there was no doubt that he had a high fever.
I decided to use the digital thermometer provided by the hospital to conduct a review, and the results showed that Xiao Ming's actual body temperature was 39.1°C. This small difference, although it may not seem large, is related to the need for antipyretics and further treatment measures. Xiao Ming's mother was surprised by the difference, and she had always trusted her old mercury thermometer to never go wrong.
This incident not only raised questions about the accuracy of mercury thermometers in Xiao Ming's mother, but also made her concerned about a broader question: why do hospitals and clinics now recommend using digital thermometers instead of mercury thermometers?
Reasons for disabling mercury thermometers
1. Environmental and health risks
Mercury is a toxic heavy metal that poses significant risks to the environment and human health. Once a mercury thermometer is broken, the mercury vapor in it can be inhaled, causing long-term damage to the nervous system, especially to children and pregnant women. This potential health risk has prompted many countries and regions to phase out the use and sale of mercury thermometers.
2. Accuracy and reliability issues
Although mercury thermometers have certain advantages in measurement accuracy, their readings are less stable and repeatable. Users need to shake the thermometer to bring the mercury back to the bottom before taking a measurement, which is error-prone and leads to inaccurate readings. In addition, mercury thermometers have a smaller scale, and visual errors can also affect the accuracy of the readings.
3. Inconvenient to use
Compared with digital thermometers, mercury thermometers are more cumbersome to use. It requires the temperature measurement area to remain still for 3 to 5 minutes, which is very inconvenient for small children or clinical settings where rapid temperature measurement is required. The fast response and legibility of the digital thermometer provide a better user experience.
4. Recycling and disposal issues
The disposal and recycling of mercury thermometers is complex and requires specialized facilities and technologies to avoid environmental pollution. Improper disposal can lead to mercury contamination of water bodies and soils, causing long-term environmental problems. These treatment costs and environmental risks are important factors in many local governments' push to ban mercury thermometers.
5. International Regulations and Policies
Many international conventions and national policies have begun to restrict or prohibit the use of mercury-containing products to reduce the pollution of mercury to the environment. For example, the Minamata Convention explicitly restricts the use and discharge of mercury and promotes the development and popularization of mercury-free medical products.
In conclusion, the ban on mercury thermometers is based on multiple considerations in terms of environmental protection, health and use. With the advancement of technology, safer, more accurate, and more convenient electronic thermometers have become the first choice, ensuring patient safety and environmental protection. In future medical practice, we will continue to find and promote medical measurement tools that are friendly to humans and the environment.
Modern alternatives
1. Digital electronic thermometer
A digital thermometer uses an electronic sensor to measure body temperature and displays the readings directly on the LCD screen. They have the advantages of fast temperature measurement, high accuracy and easy reading. Common types of digital thermometers include:
Oral thermometer: suitable for adults and older children, it is convenient to measure and has high accuracy.
Armpit thermometer: suitable for infants and young children and common use in hospitals, it is safe, but slightly inferior to the accuracy of oral thermometer.
Anal thermometer: Provides the most accurate readings for patients who need precise monitoring.
2. Infrared ear temperature thermometer
Ear thermometers use infrared technology to measure heat in the ear canal, which is a fast measurement that usually takes place in less than 1 second. These thermometers are particularly suitable for rapid screening and use by small children, as they are simple, quick and not easily affected by external factors.
3. Infrared forehead thermometer
Forehead thermometers also use infrared technology to measure body temperature by scanning the heat of a person's forehead. Their advantages include non-contact measurements, which avoids the risk of cross-contamination and are particularly suitable for use during epidemics.
4. Wearable body temperature monitoring devices
With the development of wearable technology, devices such as smartwatches and health trackers are now also appearing on the market that can continuously monitor body temperature. These devices can monitor human body temperature in real time and provide data recording and analysis through a mobile phone app, which is suitable for long-term health management and monitoring of special conditions.
5. Smart home integrated body temperature measurement
With the popularity of smart home systems, some systems have integrated body temperature measurement capabilities. For example, smart mirrors and smart bathroom scales can seamlessly integrate body temperature detection in daily use, providing a convenient health monitoring solution.
Considerations for choosing a modern thermometer
When choosing a modern thermometer, the following aspects should be considered:
Accuracy: Choose products that have proven accuracy, especially when choosing an ear or forehead thermometer.
Applicable people: Consider the age and specific needs of the user, and choose the most suitable measurement method.
Convenience: Prioritize a thermometer with fast readings and easy to operate, especially when there are small children or where there is a high need.
Extra features: Functions such as memory recording, fever alarm, glow-in-the-dark display, etc., can provide more convenience.
Brand and quality: Choose a brand with good reputation and high user evaluation to ensure quality and after-sales service.
The diversification of modern thermometers and technological advancements have provided users with more options, making body temperature measurement safer, faster, and more accurate. By making good choices, we can protect our health as well as our environment.
Recommendations for taking body temperature in daily life
1. Choose the right thermometer
For infants and toddlers: Ear thermometers or forehead thermometers are recommended because they are quick and less intrusive, making them more suitable for children who are not easily still.
For adults: Oral thermometers or ear thermometers are good choices because they are more accurate and easy to use.
For situations where precision is required: an anal thermometer provides the most accurate readings for patients who require strict temperature monitoring.
2. Use the thermometer properly
Warm-up: Before using a thermometer, make sure the device is warmed up to room temperature, especially if you use a thermometer in colder environments.
Location: Make sure the thermometer is properly placed.
Ear temperature: Pull up your ear and make sure the thermometer is pointing down the ear canal to the inside of your ear.
Oral temperature: The tip of the thermometer should be placed in the lingual fossa under the tongue, and the mouth should be closed.
Arm temperature: The thermometer must be tightly pressed against the skin and clamped under the arm.
Anal temperature: Apply lubricant to the tip of the thermometer and gently insert it into the anus.
Reading time: Follow the thermometer's instructions to ensure enough time to take an accurate reading.
3. Selection of measurement time
Daily fluctuations in body temperature: Body temperature fluctuates naturally throughout the day, usually lower in the morning and higher in the evening.
Frequency of measurement: During the illness, the temperature is measured every 4 to 6 hours to monitor the fever.
4. Interpret body temperature readings
Normal temperature range:
Ear or forehead temperature: 36.0°C (96.8°F) to 37.6°C (99.7°F)
Mouth temperature: 36.1°C (97°F) to 37.2°C (99°F)
肛温或腋温：略高于口温约0.5°C (0.9°F)
Fever test: Fever is usually considered when the ear or forehead temperature exceeds 37.6°C (99.7°F), the mouth temperature exceeds 37.2°C (99°F), or the rectal temperature exceeds 38.1°C (100.6°F).
5. Precautions and Error Avoidance
Avoid dietary influences: Avoid eating and drinking hot or cold beverages for 30 minutes before measuring mouth temperature.
Avoid the effects of activity: Avoid strenuous activity or hot baths before the measurement, which may temporarily raise body temperature.
Proper cleaning and storage: After using the thermometer, it should be cleaned with an alcohol cotton ball to prevent cross-infection, and stored according to the instructions.
With the above advice, you can effectively self-monitor your body temperature at home and detect and respond to health problems in a timely manner. Proper measurement and interpretation are key to ensuring accurate and reliable body temperature readings. In case of any abnormalities, contact a medical provider for professional advice and treatment in a timely manner.