- Dependence of temperature on the place of measurement
- Physiological fluctuations in temperature
- Types of thermometers
- How and how much to measure the temperature in the oral cavity
- Difference in indicators
- Values of normal temperature in people of different ages
- Video about normal body temperature
Body temperature is one of the few indicators, by which you can guess about the beginning of the development of the inflammatory process. An adult, unlike a child, can understand by his own state of health when the temperature is elevated and when it is within normal limits. Depending on the type of thermometer, you can also select the part of the body, the temperature of which will be measured.
Medical science has proven that indicators obtained in four places are informative:
- oral cavity;
- external auditory canal.
The values obtained in different ways have their own characteristics and differ from each other even when measuring the temperature of the same person at the same time.
Dependence of temperature on the place of measurement
When people talk about body temperature values, no one doubts that the measurements were taken in the armpit. This is indeed the most common thermometry method, it is the armpit that is the generally accepted standard for determining the temperature of internal organs.
Due to the fact that measurements in the armpit provide information on how much the skin in the fold has warmed up, it is necessary to fulfill simple, but important conditions that will make it possible to obtain a value close to the temperature of the internal organs.
First of all, to obtain a reliable result, it is necessary within 5 minutes. keep your hand pressed to your body. This will keep your skin cool when exposed to air. If the thermometer was installed without observing this condition, it will need to be held for at least 10 minutes.
In addition, the skin in the fold should be blotted with a dry cloth or otherwise removed from perspiration, as the moistened surface cools down quickly, especially if the hand, not pressed to the body, opens access to air armpit.
The last, no less important condition is the complete immersion of the thermometer tip into the skin fold. Subject to all conditions, the temperature in the armpit will be close to that of the internal organs, which will allow to correctly assess the state of health.
The known value of 36.6 ℃ was obtained by measuring body temperature of 25,000 healthy participants in the experiment. It is important that in the framework of the experiment, everyone measured the temperature in the armpit. Calculating the average, the German physician who organized the study found a value of 36.6 ℃.
For an adult and a child, when measuring their performance, it is important to compare the result obtained with generally accepted normal value only if the data was obtained after installation armpit thermometer. Temperature measured in the mouth or rectally will always be higher than normal, even in a healthy person.
Another equally popular way to find out body temperature is to insert a thermometer into the rectum. This method is called rectal. It was he who was taken as a basis in most developed countries, but not every patient agrees to such a research method.
The rectal measurement has its drawbacks:
- not aesthetically pleasing;
- the result depends on the depth of insertion of the thermometer spout;
- the value may be distorted due to the individual anatomical features of the anal ring blood supply system;
- it is dangerous to use a mercury thermometer.
Another way of measuring is tympanic. It is obtained from the human ear canal. For this measurement method, a conventional mercury thermometer will not work. Only infrared required, with ear canal attachment.
Oral temperature, as opposed to tympanic temperature, can be obtained using the most common thermometer. But it must be remembered that the values obtained outside the armpit differ from the accepted norm. The difference in measurements is shown in Table 1.
Table 1. Difference in thermometer readings obtained by different methods in a healthy adult
|Measurement type||In the armpit||In the mouth (oral)||In the rectum (rectal)||In the ear canal (tympanic)|
|Thermometer value, ℃||36,6||36,8-37,1||37,2-37,6||37,2-37,6|
Physiological fluctuations in temperature
Body temperature is not constant, and even in the absence of illness, it can rise. First of all, physiological hyperthermia is associated with overheating.
Overheating can occur in several situations:
- prolonged stay in an unventilated room;
- the presence of extra layers of clothing;
- taking certain medications;
- great physical activity;
- hormonal changes in the body.
To normalize body temperature, the body uses its own heat transfer mechanisms. If something interferes with the work of these mechanisms, heat will accumulate, resulting in hyperthermia. For this reason, the body temperature often rises in the morning, after a night's sleep. The reason lies in the lack of the habit of airing the bedroom before going to bed, excessively hot radiators, and the simultaneous use of pajamas and a warm blanket.
Stress is another common cause of fever. Under the influence of unpleasant information that provokes a stressful situation, the adrenal glands begin to secrete a large number of hormones - catecholamines.
They make the heart beat faster and increase blood pressure. The vessels expand under the action of adrenaline, the volume and speed of blood flow through the veins and arteries increase, and therefore the temperature rises. As a rule, the value of the thermometer under stress does not rise above 37.5 ℃.
Taking a certain type of medication can provoke hyperthermia. These medications include interferons: Viferon, Laferobion, Kipferon.
This is due to the fact that interferon - the main component of drugs - is produced by the body when the body temperature rises, that is, these two processes are continuously connected. When interferon appears in the blood, the center of thermoregulation reacts to this and perceives it as a signal to continue the production of the substance. For this reason, the body temperature rises to 37-37.7 ℃.
The human body gives off most of the heat with breathing. This is a natural physiological way of thermoregulation. Therefore, inhaling streams of warm air in an unventilated room, a person prevents the body from losing heat.
Women over the age of 50 notice frequent bouts of fever that are not associated with colds or inflammatory processes of a different etiology. At this age, the reproductive system begins to "fall asleep", the ovaries produce less and less sexual hormones that directly affect the number of special substances that can keep the center normal thermoregulation.
A woman begins a period of menopause, during which she can be tormented by sudden and short-term jumps in body temperature. In young girls, similar situations also occur if, for certain indications, their ovaries were removed. Then, hot flashes may appear after a short time after the operation.
Types of thermometers
You can measure the temperature not only in different parts of the body, but also with different devices. The very first and most common thermometer is mercury. Its body is made of glass and the metric rod is filled with mercury. It is this type of thermometer that is adopted as the standard for measuring hyperthermia readings.
The mercury device was replaced by an electronic one. It operates on batteries and does not pose a danger to life and health in the event of an accidental fall, unlike its glass counterpart. The downside of such a thermometer is the error in the final result.
Therefore, doctors recommend, after purchasing an electronic thermometer, to compare the readings of measurements obtained by the same method on the same person. If the results agree, the device you purchased can be trusted, and the hazardous mercury device can be removed to a safe and inaccessible place.
The temperature in the mouth (the norm for an adult ranges from 36.8-37.1 ℃) should be measured with electronic thermometers, since mercury carries a number of dangers. First of all, these are shards of glass that will injure tissues and mucous membranes if they accidentally hit the teeth.
In addition, mercury released from the device, if ingested, is a mortal danger to a person, and if it spills onto the floor, individual drops can roll into inaccessible cracks and for many years poison with their pairs everyone who lives on this territory.
Infrared thermometers are today called the most accurate. Their significant disadvantage is the high price. However, it is better to purchase an expensive, high-quality device once than to be afraid of accidentally dropping a mercury thermometer.
An infrared device takes 3-5 seconds to read from the surface of the skin or from the ear canal. It works as follows: body heat gives off infrared radiation, which is captured by the beam of a thermometer. The data is converted into a numerical value that is displayed on the device screen.
Additional functions that manufacturers give to their infrared thermometers:
- demonstration of the result in Celsius or Fahrenheit;
- memory for several measurements;
- the ability to measure the temperature of the room and water;
- built-in clock;
- display backlight;
- sound signaling about low battery level, completion of measurement, error during thermometry.
An interesting analogue of devices that can measure body temperature is a special tape that measures the readings of the skin surface. These stripes with a printed scale resemble a piece of film from an old camera. Having applied such a strip to the forehead, you can find out in a minute whether there is a main sign of inflammation in a person or not.
How and how much to measure the temperature in the oral cavity
The temperature in the mouth is the norm for an adult who drank hot tea immediately before measurements. The readings of the thermometer in the oral cavity can be influenced by the drink or food just consumed, therefore, in 15 minutes. before the procedure, it is forbidden to eat anything - after drinking a cold drink, you can distort readings downward, and by using a hot dish, on the contrary, to get false information about hyperthermia.
When using a mercury thermometer, it is important to place the tip under the tongue. This area is rich in small capillaries and blood vessels, making it easy for the device to gain access to the blood flow temperature. Keep a mercury thermometer in your mouth for no more than 3 minutes.
For children, there are special dummy thermometers with a built-in sensor in the nipple. The baby sucks on the pacifier, and on its body the display shows the measurement result. Experts warn that the beep is not an indication that the final result will appear on the screen. Electronic thermometers are designed in such a way that they react not to the achievement of thermal equilibrium with the body, but to the rate of change in readings.
While the value is growing rapidly, which is noted at the very beginning of the process, the device is silent, but when the indicator approaching the true value, tenths of a degree do not change so often, which causes the device to emit sound. Experts recommend holding it for another 1-2 minutes after the electronic thermometer gives a signal.
Difference in indicators
The temperature in the mouth, if the norm in an adult is interpreted incorrectly and is perceived as a sign of a developing pathology, may become a reason for the senseless intake of antipyretic drugs. Therapists warn that the use of antipyretics without special instructions is undesirable when the values do not exceed 38.5 ℃.
When choosing a thermometer, you should not overpay for its accuracy. The assessment of the patient's condition is carried out not by tenths of a degree, but by dynamics. However, some manufacturers are trying to significantly increase the cost of their product, declaring the accuracy of values on the packaging to 0.1 ℃. The fact that the patient needs the help of qualified specialists will not be indicated by an indicator of 38.7 ℃ or 38.9 ℃, but by the absence of a decrease in values after taking an antipyretic agent.
Or an increase in temperature while taking a drug of the NSAID group. In many situations where it is important to keep the patient in a stable condition, it is important to notice early development of hyperthermia in order to calculate the correct daily dosage of drugs and divide them by the required number receptions. An ordinary thermometer will successfully cope with this, even with an error of 0.2-0.3 ℃.
If we compare the values obtained by different devices from the same person, then one should note that the readings taken from the mercury thermometer will be closer to what the electronic analogue.
An infrared non-contact device will give values 0.2-0.5 ℃ lower than the previous two devices. This is due to the fact that the skin surface from which the infrared beam reads values is not protected from contact with ambient air. And, despite the fact that the bloodstream constantly heats it up, the skin still has time to lose some amount of heat.
Values of normal temperature in people of different ages
The temperature in the mouth, the norm in an adult which changes, depending on age, is not constant. Doctors recommend taking thermometry in the morning and in the evening in patients with a stable condition, and every two hours in patients experiencing an acute period of the disease.
Age affects the indications, because the quality and speed of blood circulation depend on the state of the vessels, the development of the circulatory system, and the elasticity of the vascular wall. Table 2 shows the values obtained when measuring oral body temperature in people of different age groups.
Table 2. Normal values for oral temperature in people of different ages.
|Patient's age, years||to 10||11-60||61 and older|
|Oral temperature, ℃||35,5-37,5||36,4-37,5||35,5-37,0|
Children under 10 years old do not yet have a fully developed endocrine system, their hormone-producing organs have not reached a mature state. Therefore, the processes of thermoregulation are somewhat different from those of the middle age group.
Elderly and elderly people already have another feature - their bodies have worn out over a long life, there is a decrease the intensity of blood flow, the volume of circulating blood decreases, hormones affecting the center of thermoregulation are produced in a smaller quantity. All this is the reason for changing the boundaries of the norm.
By measuring the temperature in the mouth, you can save time and get the most reliable information about the degree of overheating of internal organs. However, do not forget that such a research method should be carried out with a treated (sterile) device.
Children of the first two years of life are advised to purchase special dummy thermometers, and discuss any deviations from the norm by more than 0.5 ℃ with a pediatrician. For adults, it is better to make a choice in favor of a classic, inexpensive electronic device, rather than a mercury device, so that the research itself does not become a threat to life and health.
Author: Rudich Anastasia
Video about normal body temperature
Body temperature in the mouth in normal and pathological conditions: