Measurement of body temperature: where, how, and how accurately

Biologically, a person is a warm-blooded being. This means that to ensure the normal course of physiological processes in the body, it must maintain body temperature in a fairly narrow range. On average, it is +36.4 ... + 36.8 degrees. Increasing this temperature by only half a degree means that the defenses of the organism have entered into a battle with an infectious invasion, or there is a serious disruption in the functioning of a vital organ, and the development of inflammation proceeds. Lowering the temperature also indicates a pathology. Thus, measuring the temperature of a person's body is the basic procedure for determining whether the body's systems work correctly, whether it is healthy.

Where to measure

In the "healthy" state of the human body, the temperature is constant and independent of the environment. Despite this, the organs and tissues of a person have different temperatures. If the skin is healthy at +29.5, then the liver is at +38. On the contrary, the brain has the most constant and stable thermal regime. However, the technique of measuring body temperature should show the value closest to the thermal state of internal organs.

This is achievable in rectal temperature measurement, when the measuring element of the thermometer is injected into the rectum. But with diarrhea, constipation and critical days in women, the values obtained are significantly different from the real ones. Also this method of measurement is contraindicated in diseases of the rectum.

The most common measurement of body temperature is a mercury thermometer in the armpit. The values obtained are less than in the rectal measurement by half a degree and are +36.5 ... + 37.0.

In the United Kingdom and the United States, body temperature is measured orally (in the oral cavity). To do this, place the measuring element of the thermometer under the tongue. Here the temperature is more than in the armpit, by 0.3 degrees. Measurements lose their accuracy with inflammation in the oral cavity and diseases of the respiratory tract. For young children, this method is not suitable because of the danger of injury.

Also, the familiar "mother method" (applying the palm to the forehead) found its application in the modern measurement method using infrared technology.

Finally, rarely, but the temperature in the ear canal is measured, for which the same infrared thermometers are used. Inflammation in the ear distorts the readings.

How to measure

Despite the fact that the world is gradually giving up mercury thermometers for understandable reasons, they are still leaders in terms of the "price-measurement accuracy" ratio. They can perform axillary, oral and rectal measurements (the latter two with caution), they are easy to disinfect. To get the result, you have to wait 10 minutes.

Safe and very quickly measure the temperature of electronic thermometers (they are also called digital thermometers ). But they are sensitive to moisture in contrast to the glass thermometer, give an error of 0.1-0.2 degrees, cheap models can not be disinfected, at the most crucial moment the battery may run out.

Relative novelty is the measurement of body temperature by infrared thermometers. The most perfect of them do not require disinfection at all by non-contact measurement. Ideal for children, as they can not be undressed, get the temperature values of the sleeping, and all this in a matter of seconds. However, just like electronic ones, they have an error and are very expensive.

For the very young, a digital thermometer was invented to measure body temperature in the form of a pacifier. It gives the desired values within 3-5 minutes.

There are also thermal bands based on a sensitive film. The exact figure, however, they do not give, just show the limits in which the temperature is located. The indications are influenced by skin sweating and tightness of the thermo band to the body.

If the measurement of body temperature is inaccurate, then it may not be the instruments that are to blame, but people who do not bother to read the instructions for use before use.