Forehead temperature is generally measured by frontal temperature gun, body temperature in 35.0-37.0 ℃ is normal, more than 37 ℃ as fever. However, using frontal temperature gun to measure the forehead temperature is often affected by the external environment and produce errors, such as measuring the forehead temperature immediately after sunbathing, which may make the forehead temperature slightly higher than the body temperature. If the frontal temperature is measured outdoors in the cold winter, it will definitely be lower than the normal body temperature. Therefore, to avoid these situations, it is most accurate to measure the frontal temperature in the room at room temperature. If there is sweat on the forehead, dry the sweat, because sweat on the forehead will take away part of the heat, which will also make the forehead temperature lower than the normal body temperature. The location of the body temperature is often measured in the armpit, under the tongue or anus, especially the armpit and under the tongue temperature. Axillary temperature is between 36.0-37.0°C, sublingual temperature is between 36.3-37.2°C, and rectal temperature is between 36.5-37.7°C. A temperature greater than the upper range can be classified as feverish.