The baby’s body temperature of 35.8 ℃ is not normal, the body temperature is slightly low, the normal children’s body temperature (based on the axillary temperature) should be between 36 ~ 37 ℃, need to exclude the measurement error. Children’s underarm temperature measurement refers to dry sweat, the thermometer head end placed deep in the armpit, the patient clamped the upper arm for measurement, 10 minutes after the readings, simple and convenient, the normal value should be 36 ~ 37 ℃, there are fluctuations. Baby body temperature if below 36 ℃, for hypothermia. Most often seen in the clothing is too little, the environment temperature is too low, did not pay attention to warmth, insufficient energy intake, etc., but also may be infected and other diseases affect. When taking temperature, you should pay attention to whether there is any error in the way the temperature is measured, and rule out measurement errors, such as whether the measurement time is too short, or the underarm thermometer is not clamped. If the temperature does not rise after eliminating errors, keeping warm and eating, it is recommended to go to the hospital in time to clarify the cause of hypothermia and actively carry out targeted treatment or therapy.