How many degrees indicate a fever in children?
Sep 05, 2025
Source: Cainiu Health
Dr. Zhou Xiaofeng
Introduction
In general, determining whether a child has a fever depends on the body site used for temperature measurement. Common methods include measuring under the armpit (axillary) and in the mouth (oral), and the criteria for fever vary according to the measurement site. When taking the temperature, avoid doing so immediately after the child has exercised, eaten, or cried. Wait until the child has been calm for 30 minutes to reduce measurement errors.
Generally, determining whether a child has a fever depends on the specific body site where the temperature is measured. Common methods include measuring under the armpit (axillary) or in the mouth (oral), and the criteria for fever vary according to the measurement site. Detailed analysis is as follows:
The armpit is the most commonly used measurement site, with a normal body temperature range of 36.0°C to 37.2°C. If the measured temperature exceeds 37.3°C, it can be determined as a fever. A temperature of 37.3°C to 38.0°C is considered a low-grade fever, 38.1°C to 39.0°C is a moderate fever, and anything above 39.1°C is considered a high fever. When measuring, place the thermometer under the child's armpit and hold it in place for 5 to 10 minutes to ensure an accurate reading.
The normal oral temperature range is 36.3°C to 37.5°C. If the oral temperature exceeds 37.5°C, it indicates the child has a fever. The classification criteria for body temperature are consistent with those for axillary measurements. Before measuring, ensure there is no hot or cold food in the child's mouth. Place the thermometer under the tongue and wait for 3 to 5 minutes before reading the value.
When measuring body temperature, avoid taking the measurement immediately after the child has exercised, eaten, or been upset. Wait until the child has calmed down for 30 minutes before taking the measurement to reduce errors. If the child's temperature is slightly elevated, wait a while and measure again to observe the trend of temperature change.
