
Fever occurs when a part of the brain called the hypothalamus shifts the set point of your normal body temperature upward. When this happens, you may feel chilled and add layers of clothing, or you may start shivering to generate more body heat. This eventually results in a higher body temperature.
There are numerous different conditions that can trigger a fever. Some possible causes include:
- infections, including the flu and pneumonia
- some immunizations, such as diphtheria or tetanus (in children)
- teething (in infants)
- some inflammatory diseases, including rheumatoid arthritis (RA) and Crohn's disease
- blood clots
- extreme sunburn
- food poisoning
- some medications, including antibiotics
Depending on the cause of the fever, additional symptoms may include:
- sweating
- shivering
- headache
- muscle aches
- loss of appetite
- dehydration
- general weakness
Read more at: https://www.healthline.com/health/fever