It is generally lowest upon awakening in the morning. Food, extra clothing, excitement , and anxiety can all raise the body temperature. Strenuous exercise can temporarily raise body temperature to as high as 103 degrees Fahrenheit. Extreme exercise, such as a marathon or a seizure, can raise body temperature to 107 degrees Fahrenheit. A woman's menstrual cycle can also elevate temperature by one degree or more.
Most children have higher body temperatures than adults and seem to have more daily variation.
Many infants and children develop high fevers, even with minor viral illnesses. A high fever does not directly cause brain damage. However, febrile seizures can occur in some children, and the seizure can cause injury to the child. Bacteria, viruses, or their toxins may be released into the bloodstream and cause chills and shivering in the patient. Chills may occur during a temperature spike within a fever.