Children with fever generally choose to measure the axillary temperature or use electronic thermometers to measure directly on the forehead and behind the ear. The disadvantage of electronic thermometers is that they are less accurate, less used in clinical practice, and require regular correction. The common parts of the body temperature measurement are the armpit, mouth and rectum, because the risk of biting the thermometer when measuring the mouth can easily occur, which can lead to accidental ingestion of mercury. The rectal area is painful and the child will not cooperate. Therefore, the axillary temperature is most commonly used and is usually measured with a mercury thermometer. Children are more likely to have a fever because their thermoregulatory center is not well developed. By measuring the axillary temperature, you can check whether your child has a fever or the exact degree of fever. You should always observe your child’s temperature change and mental state. The axillary temperature is usually less than 37℃ and more than 37.3℃ is considered fever.