1. Symptoms of infant fever Infant fever refers to the phenomenon that the body temperature rises above the normal body temperature by more than 37.5℃. In addition to an increase in body temperature, other physical reactions may occur, such as dry mouth, loss of appetite, headache, muscle aches, etc. If your baby develops these symptoms, you must take timely measures. 2. Causes of fever in infants There are many causes of fever in infants, the most common of which is infection. Infections can come from many aspects such as the respiratory tract and digestive tract, such as colds