The answer is that it is not necessary. But why do many doctors also say that 0.5℃ should be added? I have consulted with doctors who believe that 0.5°C should be added, and their general opinion is as follows: the axillary temperature that we often measure does not represent the internal temperature, and 0.5°C needs to be added to represent the actual internal temperature. It seems that the patient’s view that 0.5°C should be added actually comes from some of the doctors. To clarify this issue we may want to look at the definition of body temperature. Physiology, when studying human body temperature, divides it into two parts: core temperature and surface temperature. In clinical practice, we often refer to the average core temperature (note that it is the average temperature). Obviously, this average temperature is not easy to measure, and we cannot dismantle the body in order to measure a core temperature. Since the temperature of the deeper organs of the body converges through the exchange of heat in the circulating blood, the temperature of the deeper blood of the body can represent the average of the temperature of the internal organs. But the deep blood temperature is not easy to measure, and it is impossible to make an intervention in order to measure a body temperature. So how to do it? You must know, is to find a few places on the surface of the body can form a closed cavity to measure the temperature to represent the body temperature. The oral cavity, the rectum, the closed armpit, and the ear canal tympanic membrane (slightly different principle) are very good choices. The axillary temperature, rectal temperature (anal temperature), and oral temperature have been established to correspond to the reference range, such as the normal reference value of axillary temperature is: 36 ℃ – 37.4 ℃ (different information may have a difference of 0.1-0.2 ℃). A baby measure axillary temperature 37.3 ℃, you have to add 0.5 into 37.8 ℃ that the baby has hypothermia is not necessary. That’s right. The temperature we take is not the core temperature, but our temperature standard is not the core temperature standard either. Therefore, there is no need to add 0.5°C. Having said that, the fact is that adding or not adding 0.5°C has no impact on the diagnosis and treatment of clinical disease in the vast majority of cases. But the words should be clear!