1. Causes of baby\’s fever Baby\’s fever is caused by foreign substances such as bacteria and viruses inside the body, or it may be caused by overwork or immune disorder. When a baby is infected with bacteria or viruses, the body produces immune cells called white blood cells to fight against these foreign substances, causing fever. 2. How to judge whether the baby has a fever. Under normal circumstances, the normal body temperature of the human body should be between 36.5℃~37.5℃. When the baby\’s body temperature exceeds 37.5℃