Is a temperature of 39 degrees considered a high fever?

Fever is a common symptom. There are three main ways to measure human body temperature. One is to measure oral temperature, one is to measure rectal temperature, and the most common one is to measure axillary temperature. Generally speaking, the normal temperature of the human body is 37 degrees. If the temperature reaches 39 degrees, it is considered a high fever. Patients with high fever must take timely measures to reduce the temperature and then go to the hospital for treatment.

1. Temperature measurement

Normal body temperature Normal body temperature varies slightly depending on the test site. Commonly used body temperatures include: oral temperature, rectal temperature and axillary temperature.

(1) Oral temperature

Place the thermometer under the patient's tongue and remove it after closing the mouth for about 3 minutes. The normal range is 36.3℃～37.2℃;

(2) Rectal temperature

The measurement method is to disinfect the thermometer, apply lubricant, insert it into the anus, and remove it after three minutes. The normal value is about 0.3℃ to 0.5℃ higher than the oral temperature.

(3) Axillary temperature

Because the measurement is convenient and hygienic, it is the most commonly used temperature measurement method at present. The measurement method is to clip the thermometer under the armpit and read the value after five minutes. The normal range is 36.1℃~37℃, which is about 0.2℃~0.4℃ lower than the oral temperature.

When measuring body temperature, be sure not to confuse the normal values ​​of the three measurement methods.

2. Normal changes in body temperature

Under the influence of internal and external factors, body temperature may vary slightly within the normal range. For example, the body temperature in the afternoon is relatively higher than in the morning, but the difference is generally less than 1°C; the body temperature may also rise slightly after a meal, work or strenuous exercise; factors such as suddenly entering a high temperature environment or being emotionally excited can also cause the body temperature to rise slightly; women's body temperature is slightly higher than normal during ovulation and pregnancy. There are also slight differences in body temperature at different age stages. For example, children have higher body temperature than adults due to their high metabolic rate; the elderly have slightly lower body temperature than young and middle-aged people due to their low metabolic rate.

3. Several cases of fever

There are parts of the human body that are specifically responsible for managing body temperature regulation (the cerebral cortex and hypothalamus). We call it the body temperature regulation center. It regulates the body's heat production and heat dissipation through nerves, body fluids and other factors, so that body temperature fluctuations are within the normal range. Therefore, the body temperature of a healthy person can remain relatively constant. Some exogenous or endogenous substances can act on the body temperature regulation center, destroying the dynamic balance between heat production and heat dissipation, causing the body to show fever. Medicine collectively calls these substances that can cause fever pyrogens. Of course, dysfunction of the body temperature regulation center itself can also cause fever. According to the degree of fever (oral temperature), it can be divided into: low fever: 37.4℃～38℃; moderate fever: 38.1℃～39℃; high fever: 39.1℃～41℃; hyperpyrexia: above 41℃.

Since the body's heat energy mainly comes from skeletal muscle, under the action of pyrogens, skeletal muscle contracts particularly strongly, so before the body temperature rises, patients often feel cold and have chills, followed by high fever. Fever itself is not a disease, it is just a clinical manifestation of a certain disease. When taking symptomatic treatment for fever, do not forget to take further measures based on the cause of the fever and go to the hospital for treatment if necessary.