What is the Normal Body Temperature for a Person?

There is a certain difference in our body temperature between morning and evening. Even when infected with a disease, the body temperature can rise. Therefore, abnormal body temperature can help us detect diseases in time and seek treatment. Generally speaking, our body temperature ranges from 36 to 37 degrees Celsius, with oral temperature ranging from 36.3℃ to 37.2℃, and axillary temperature being 0.2℃ to 0.5℃ lower than oral temperature. Any temperature exceeding these ranges is considered abnormal.

1. Body temperature measurement: Normal body temperature may vary slightly depending on the test site. Commonly used body temperature measurements include: oral temperature, rectal temperature, and axillary temperature.

(1) Oral temperature: Place the thermometer under the patient's tongue, close the mouth, and remove it after about 3 minutes. The normal range is 36.3℃ to 37.2℃.

(2) Rectal temperature: After disinfecting the thermometer, apply lubricating oil and insert it into the anus. Remove it after three minutes. The normal value is about 0.3℃ to 0.5℃ higher than the oral temperature.

(3) Axillary temperature: Due to its convenience and hygiene, axillary temperature measurement is currently the most commonly used method. Place the thermometer under the armpit, wait for five minutes, and read the value. The normal range is 36.1℃ to 37℃, slightly lower than the oral temperature by 0.2℃ to 0.4℃.

When measuring body temperature, it is important to remember the normal values for each measurement method to avoid confusion.

Body temperature can vary slightly within the normal range due to internal and external factors. For example, body temperature in the afternoon is relatively higher than in the morning, but the difference is generally less than 1℃. Body temperature may also rise slightly after eating, engaging in physical labor, or intense exercise. Sudden exposure to high temperatures or emotional arousal can also cause a slight increase in body temperature. Women's body temperature is slightly higher than normal during ovulation and pregnancy.

There are also slight differences in body temperature among different age groups. Children tend to have higher body temperatures due to their high metabolic rate, while the elderly may have slightly lower body temperatures due to their low metabolic rate.

There are specific areas in the human body (the cerebral cortex and hypothalamus) responsible for regulating body temperature, known as the thermoregulatory center. This center regulates heat production and dissipation through neural and humoral mechanisms to maintain body temperature within a normal range. Therefore, healthy individuals can maintain a relatively constant body temperature.

External or internal substances can act on the thermoregulatory center, disrupting the dynamic balance between heat production and dissipation, resulting in fever. These substances that can cause fever are collectively referred to as pyrogens. Additionally, dysfunction of the thermoregulatory center itself can also cause fever.

Fever can be classified based on its severity (measured by oral temperature) as follows: low-grade fever: 37.4℃ to 38℃; moderate fever: 38.1℃ to 39℃; high fever: 39.1℃ to 41℃; and super high fever: above 41℃. Since the body's heat mainly originates from skeletal muscle, under the influence of pyrogens, skeletal muscle contraction becomes particularly intense. Therefore, patients often experience chills and shivering before their body temperature rises, followed by high fever.

Fever itself is not a disease but a clinical manifestation of certain illnesses. When treating fever, it is important to address the underlying cause and seek further medical attention if necessary.