It can fluctuate from 36.5 to 37.5 degrees normally. Mild elevations of 38 to 38.5 degrees C can be caused by exercise, excessive clothing, a hot bath or hot weather. Breast and bottle feeding, warm food or drink can cause a rise in temperature for about half and hour. If one of the above causes is possible it is important to take the temperature again. Causes of Fever Fever is a symptom not a disease.
Fever is a normal response to infection and helps to fight infection.
A fever activates the body's immune system. A fever of 37.8 to 40 degrees C is not harmful. Most are due to viral illness and some are due to bacteria. Teething does not cause a fever over 38.4 degrees C. Expected Course of Fever Viral fevers are usually between 38.3 and 40 degrees C and persist for 2 to 3 days. The level of fever does not necessarily directly relate to the seriousness of an illness.