What is a fever?
Body temperature is regulated in the human brain and in the hypothalamus. Often the body temperature is between 35 and 37 degrees. But in different people, there is a possibility of a one-degree error. As you know, fever is not a disease but the only sign of a disease in the body. Bacteria and viruses mainly cause infections in the body, and infection caused by the virus activates white blood cells. This interaction between the cells in the body causes fever, the message of the body’s involvement with bacteria or viruses reaches the brain, and the brain instructs the hypothalamus to raise the body temperature.
A thermometer is a medical device that measures body temperature. These devices are marketed in a variety of digital contact and non-contact mercury.
Measuring body temperature
From a medical and health point of view, measuring body temperature is of special importance. As you know, fever is one of the symptoms of many diseases. By measuring the fever, it is possible to understand what stage the disease is in and to follow the treatment process. According to experiments, the measured temperature of the human body is related to the ambient temperature in which it is located. For this reason, contrary to many beliefs, normal body temperature can not be measured accurately. Also, people’s body temperature changes based on their daily activities.
In rectal temperature measurement, temperature tolerance of 0.5 ° C is known as a physiological phenomenon. As you know, body temperature rises mainly after physical activity. The core temperature is different from the body surface temperature. The body surface temperature is obtained by measuring the temperature of the skin, while to measure the core temperature, the temperature of the mucous tissue of one of the body cavities must be measured.
The normal body temperature based on the age factor is expressed in the table below.
Methods of measuring temperature based on body organs
There are several methods for measuring body temperature, the most common of which are as follows.
Rectal measurement, vaginal measurement, oral measurement, axillary or groin temperature measurement through ear canal or forehead. In the following, we will explain the correct way to measure temperature based on the type of thermometer selected.
Mercury medical thermometer
This thermometer is the oldest model of medical thermometers that is used to measure temperature by rectal, vaginal, oral and other methods of measuring through the groin, armpits and ear canal.
Measurement through the forehead
This method is one of the most common methods of measuring body temperature, very accurate and easy. In this method, the thermometer places a non-contact sensor or thermometer on the forehead, and the device measures the highest body temperature. In another model of thermometers, the device has two sensors to measure the ambient temperature and the body (body). In this method, the results of the two measurements are analyzed based on clinical cases and the body temperature appears on the screen.
Non-contact digital thermometers
Non-contact thermometers use infrared temperature sensors to measure body and body temperature. These thermometers are marketed as medical laser thermometers or infrared thermometers and even thermovision ( thermal imaging camera ).
Laser thermometers
Laser thermometers use an infrared sensor to measure temperature and detect infrared radiation from body heat. Laser thermometers are sold under brand names for body temperature, general and industrial, which according to research are exactly the same in terms of accuracy and measurement, and even industrial models have a higher accuracy.
To use non-contact thermometers, including the phone, the forehead that you see in the picture above. Adjust your thermometer to the desired measurement mode according to the user guide. The following video is completely how to measure by a special model of these thermometers Explains to you.
When using the industrial model to measure body temperature , thermometers with the ability to adjust the radiation coefficient should be used. To measure, be sure to calibrate your device. My technical colleagues, based on my personal experience, have a radiation coefficient of 95 to measure the body. They recommend, but to ensure calibration, read the following text. Note that some industrial thermometers have a constant radiation coefficient. This equipment is sometimes also suitable for measuring general body temperature. The sample measured by this special device can be found in the size test film. See temperature in the lower parts of the text.
Calibration of non-contact thermometer by radiation coefficient
To calibrate a laser thermometer, you need a medical or conventional mercury thermometer. These types of thermometers are automatically calibrated by the factory. First, measure the point temperature of your body or forehead with a mercury thermometer. The user guide of each model of laser thermometer describes how to equalize the displayed temperature with the temperature reading of the thermometer. Now your device is ready to measure the forehead temperature from a distance of 10 to 20 cm. Watch the video below to learn how to calibrate.
Medical laser thermometers
But medical thermometers that are used to measure body temperature in a specialized way, as stated in the sections above, are designed precisely to measure body temperature. They have an easy-to-use interface and age selection, as well as a core temperature calculation formula. They use the same technology as industrial thermometers, but in the form of body thermometer structure to measure forehead and ear temperature, and in contact models rectal temperature and below. They are used in the armpits and oral use includes these cases, but the oral method has been prohibited for years for health reasons. According to the table below:
These devices measure body temperature based on the following model and based on the special formula described below.
It is impossible to obtain the absolute body temperature by thermometers and it is very difficult and time consuming even for physicians armed with various measuring equipments. Therefore, average parameters and special coefficients are used to calculate the average body temperature to obtain the temperature. Body factors such as the amount of work W, the amount of heat reduction through evaporation of body fluids E and heat transfer to the environment through convection c and radiation or radiation R are considered. The formula for measuring average body temperature, including average tb and average skin surface temperature, respectively. tsk and the temperature of the eardrum are trs and constant k. For this purpose, medical thermometers are programmed with the following formula and relations such as these.