Normal body temperature in children.
The exact limits of normal body temperature can not be designated. As well as in the measurement of other physiological indicators, not only a wide range of the norm is detected here, but also a significant overlap between the temperature values in healthy people and in patients.
Dubois believes that the normal normal rectal temperature range is from 36.1 ° C to 37.8 ° C, and the oral temperature is from 35.8 ° C to 37.3 ° C, in the armpits in the region of 36.6 ° C.
However, he did not indicate that a temperature as high as 40 ° C and as low as 35 ° C could be observed in healthy people in some circumstances.
Due to the work of the thermoregulation center, which is located in the preoptic region of the hypothalamus, an equilibrium between heat production and heat transfer is usually achieved in order to maintain the “core” temperature within normal limits, i.e. not just one fixed temperature, but the temperature within the normal range. What factors determine the actual body temperature at any given moment?
Circadian rhythm (changes in normal) body temperature in children
Daily fluctuations, or circadian rhythm – this is a regular change in body temperature during the 24-hour cycle. This phenomenon in humans is very noticeable and can cause a temperature difference between the zenith and nadir of the cycle, ranging from 0.27 ° C to 0.82 ° C. The body temperature falls at night, reaching a low point of about 3 hours, and then gradually rises to a peak at 17-18 hours.
The circadian rhythms of different people vary, but remain very constant in the individual. This cycle is also relatively independent of human activity (during work, in a dream), although it is assumed that it can be violated or even become the opposite of people sleeping during the day and working at night.
The circadian rhythm is absent in newborns and young children and is established after the second year of life, and it is relatively more noticeable in children than in adults. Thus, the difference between the highest and lowest points of the temperature cycle in children is greater than in adults. In children, this difference can reach 1.4 C. Daily temperature fluctuations are more significant in girls than in boys.
Circadian fluctuations, to some extent, also occur during febrile illnesses. It is well known that sick children have a higher fever in the evening, not early in the morning. In one study, it was found that over an 8-hour period (from 4 to 4 pm) 82% of visits to the pediatrician were associated with fever, whereas only 46% of all calls to the pediatrician fell on the same period of time.
Feverish diseases, even long ones, usually do not disturb the main circadian rhythm, which is restored immediately after the disappearance of the fever.
The clinical significance of circadian rhythm is multifaceted. Knowledge of normal daily temperature changes helps the doctor to avoid incorrect assessment of moderately elevated evening temperature as a fever or an incorrect judgment about the “subnormal temperature” in the early morning hours. In neurological patients, a normal circadian rhythm suggests that the mechanism of thermoregulation is not damaged. Finally, the lack of circadian rhythm makes it possible to suspect a false fever.