What counts as a fever is indeed a very complicated issue. In addition to taking the temperature, it is important to carefully observe the various signs of the child. A normal temperature increase? A child’s body temperature fluctuates easily. Infections, the environment, and exercise are all factors that can cause a child’s temperature to change. An increase in a child’s temperature is not necessarily abnormal, that is, an increase in temperature is not necessarily a fever. If there is a brief fluctuation in temperature, but the general condition is good and there are no other abnormalities, parents should not assume that their child is running a fever. In fact, just as our body temperature rises after exercise as adults, it also rises after normal physiological activities such as crying and breastfeeding in children. In general, the body temperature does not rise too high, mostly between 37.5℃ and 38.0℃. The increase in body temperature is due to normal physiological activities such as crying and breastfeeding that result in more heat being produced by the muscles. The elevated body temperature due to these causes will return to normal levels soon after the end of exercise. In other words, body temperature alone should not be used as an indicator to determine abnormalities. When these conditions are encountered, parents can continue to observe changes in their child’s body temperature and generally do not require any treatment. Normal human body temperature fluctuates within a certain range: the general axillary temperature is 36°C to 37.4°C. A body temperature above 37.5°C is defined as fever, commonly known as a fever. It is further divided into: 37.3℃～38℃ as low fever; 38.1℃～39℃ as moderate fever; 39.1℃～41℃ as high fever; and over 41℃ as ultra-high fever. Abnormally elevated body temperature (fever): Abnormally elevated body temperature is also known as fever, which is different from the elevated body temperature caused by crying. In fever, there is not only an increase in body temperature, but also other abnormal manifestations caused by the disease, such as pallor, accelerated breathing, emotional instability, nausea, vomiting, diarrhea, rash, etc. The manifestations and course of fever vary greatly depending on the individual child and the cause of the disease. For example, in the case of pneumonia, some children have a low fever, while others have a high fever of 39-40°C. Another example is that fever in upper respiratory tract infections can last 2-3 days, while sepsis can last several weeks. The onset of fever can be acute or slow, some have chills followed by fever, and some have high fever but cold extremities and forehead. Therefore, it is difficult to detect fever by touching the extremities and forehead with the hand, while touching the chest and abdomen will make the child feel feverish. The question of what constitutes a fever is indeed a very complicated one. In addition to taking the temperature, it is also necessary to carefully observe the child’s various manifestations. On the one hand, you can have a good idea, and on the other hand, you can provide your doctor with more reliable information.