Children catching a cold is a common occurrence, often accompanied by varying degrees of fever. Accurate temperature measurement is crucial for timely treatment with specialized medications. The most frequently and accurately measured temperature is the rectal temperature, as it is closest to the core body temperature. This measurement typically uses a mercury thermometer and takes about three minutes. If a mercury thermometer is not available, an infrared thermometer can also be used to measure the baby's ear temperature. Ear temperature also closely approximates the core body temperature. However, during measurement, it is essential to straighten the ear canal as much as possible to keep it in a straight line for accurate results. If it is not possible to measure the rectal or ear temperature, then measuring the forehead temperature is an alternative. However, the temperature on the forehead is generally about 0.5℃ lower than the rectal or ear temperature. This measurement is more affected by various factors and has a larger margin of error, which needs special attention.