Neonatal baby’s thermoregulatory center and sweat gland tissue development is immature, the degree of heat tolerance and response are relatively poor, heat production and heat dissipation function are not perfect, the regulation ability is poor, plus the newborn subcutaneous fat is thin, the body surface area is relatively large, body temperature is susceptible to the surrounding environment temperature. Therefore, in the excessive warmth, wrapped too much, or in the summer indoor temperature higher than 30 degrees, can cause the newborn body temperature rise, so many factors can cause neonatal fever. The main clinical manifestations are as follows: 1. The most typical symptom is an increase in body temperature, which is generally feverish when the body temperature exceeds 37.3 degrees Celsius, 37.3-38.0 degrees Celsius for low fever, 38.1-39.0 degrees Celsius for moderate fever, 39.1-40.0 degrees Celsius for high fever, and over 41 degrees Celsius for ultra-high fever. 2. Skin vasodilation, facial and skin flushing, respiration may be intensified and accelerated, there may be sweating, decreased urine volume and yellow urine. It may also show pale skin, dry mouth and lips, and no sweating. 3, the baby may also appear crying, irritability, fatigue, loss of appetite, reduced feeding or refusal of milk, choking, emotional instability, depression, high fever sometimes can also appear high fever convulsions, with different degrees of convulsions. 4. In severe cases, there may be chills in the limbs, skin blossoms, and even serious symptoms such as blue face and respiratory arrest, so you should go to the hospital in time to avoid delaying the condition.