Why Does Body Temperature Rise?
Generally speaking, there are slight fluctuations in our body temperature, such as differences in temperature between morning and evening, but the differences are not significant. Only when the body is ill, the temperature will rise. For example, when we have a fever or a cold, our body temperature will rise. If it reaches 40 degrees Celsius, it can cause problems in some organs. In addition to fever and cold, there are other reasons, such as high fever caused by psychological factors.
High body temperature refers to a condition where the set point of the thermoregulatory center shifts upward due to various reasons, resulting in an increase in body temperature beyond the normal range. It is also known as fever, which is caused by excessive heat production, reduced heat dissipation, thermoregulatory dysfunction, or the action of pyrogens on the thermoregulatory center, leading to an upward shift in the set point and subsequent increase in body temperature beyond the normal range. Generally, when the axillary temperature exceeds 37°C or the oral temperature exceeds 37.5°C, and the temperature fluctuation exceeds 1°C within a 24-hour period, it can be considered as high body temperature.
There are many causes of high body temperature, with infection being the most common one (including various bacterial infections, viral infections, mycoplasma infections, etc.). Other causes include connective tissue diseases (collagen diseases), malignancies, etc. High body temperature can have both beneficial and harmful effects on the human body. When the body temperature rises, the immune function is significantly enhanced, which is beneficial for clearing pathogens and promoting recovery from illness. Fever can also be a sign of illness, so when the body temperature is not too high, drinking plenty of water can help reduce the discomfort caused by high body temperature. Antibiotics (such as penicillin) are not necessary for high body temperature caused by non-bacterial infections. Warm glucose water can help with urination and cooling, and physical methods can be used to control the body temperature when it does not exceed 38.5°C. However, if the body temperature exceeds 40°C (or 39°C for children), it may cause symptoms such as dizziness, convulsions, shock, and even serious sequelae, so medical attention should be sought promptly. In case of symptoms such as convulsions, sedatives should be taken as prescribed by a doctor (especially for children).
High body temperature is caused by the activation of fever-inducing substances in the body, which leads to the production of endogenous pyrogens (EP) and their entry into the brain to act on the thermoregulatory center. This further leads to the release of fever-mediating substances, resulting in changes in the set point and ultimately causing fever. Common fever-inducing substances come from external sources such as bacteria, viruses, fungi, spirochetes, malaria parasites, etc., as well as internal sources such as antigen-antibody complexes and steroids. Endogenous pyrogens (EP) come from EP-producing cells in the body, and their main types include interleukin-1 (IL-1), tumor necrosis factor (TNF), interferon (IFN), interleukin-6 (IL-6), etc. EP acts on the thermoregulatory center located in the POAH, causing the production of positive and negative regulatory mediators. The latter can cause changes in the set point and ultimately lead to the production of fever.
High body temperature is not a disease itself but a symptom. In fact, it is one of the mechanisms for resisting infection in the body. Fever may even have its uses, such as shortening the duration of illness, enhancing the effectiveness of antibiotics, and making the infection less contagious. These benefits should outweigh the discomfort experienced during fever.
