Clinical Thermometers and Children's Health - Part II

Understanding Body Temperature Measurement

Body temperature is a vital indicator of health, typically reflecting the temperature of the blood. The accuracy of this measurement can be influenced by various factors including recent physical activity, the level of clothing, and the surrounding environmental conditions. It's important to choose the right method and type of thermometer to obtain an accurate reading.

Preferred Methods for Children

• Rectal Temperature: Although this method is highly accurate, it is generally not recommended for untrained individuals to use on children due to discomfort and potential for slow response to changes in core body temperature.
• Axillary Temperature (Armpit): This is the simplest and most common method for young children, especially under three months old. However, it is also the least accurate. Proper placement over the axillary artery is crucial and can be challenging with an uncooperative child.
• Oral Temperature: Suitable for older children who can hold the thermometer under their tongue, this method is more accurate than an axillary reading but requires the child's cooperation.
• Tympanic Temperature (Ear): This method involves measuring the temperature in the ear canal, close to the core temperature. Modern tympanic thermometers are designed to be unaffected by ear wax and provide a quick and accurate measurement, though they are not recommended for infants under three months.

According to a study published in the Pediatrics International journal, tympanic thermometers show a high degree of accuracy comparable to rectal thermometers, making them a preferred choice for quick assessments in older children (source).

Types of Thermometers

• Digital Thermometers: These have largely replaced glass thermometers due to their safety and accuracy. They are available for various specific uses such as tympanic, rectal, and oral/axillary.
• Plastic Strip or Dot Thermometers: These thermometers stick to the skin and change color to indicate temperature. They are generally used for a quick indication of elevated temperature but are not accurate for precise measurements.
• Pacifier Thermometers: Shaped like a baby’s pacifier, these thermometers are appealing for infants but require the pacifier to stay in the mouth for a prolonged period, which can be impractical.

A 2017 report by the American Academy of Pediatrics advises against the use of pacifier thermometers due to their potential inaccuracies and recommends digital thermometers for children of any age (source).

How To Use A Thermometer Effectively

Always follow the manufacturer’s instructions closely. Here are some general guidelines:

• Oral Readings: Ensure the child hasn't eaten or drunk anything hot or cold for at least 15 minutes before taking a reading. Place the thermometer under the tongue and ask the child to hold it steady.
• Axillary Readings: Remove any clothing from the armpit, locate the axillary artery, and place the thermometer directly over it. Hold the child’s arm across their chest to secure the thermometer in place.
• Rectal Readings: Use only if necessary and with proper lubrication. Gently insert the thermometer about an inch into the anus without forcing it.

When to Consult a Doctor

If your child’s temperature reaches 38°C (100.4°F) or higher, it is advisable to consult a doctor. This threshold, as noted by the Mayo Clinic, is a common indicator of fever that may require medical attention (source).

By understanding the proper use and types of clinical thermometers, parents can more effectively monitor their children's health and make informed decisions about when to seek medical care.