A fever is a temporary rise in body temperature and is one part of an overall response from the bodys immune system. In adults, a fever is usually defined as a body temperature of 100.4°F (38°C) or higher. However, body temperatures can vary slightly from person to person and at different times of the day. Depending on whats causing a fever, other fever signs and symptoms may include:
- Sweating
- Chills and shivering
- Headache
- Muscle aches
- Loss of appetite
- Irritability
- Dehydration
- General weakness
If an adults temperature is 103°F (39.4°C) or higher, they should call their healthcare provider. Seek immediate medical attention if any of the following signs or symptoms accompany a fever:
- Severe headache
- Rash
- Unusual sensitivity to bright light
- Stiff neck and pain when you bend your head forward
- Mental confusion, strange behavior, or altered speech
- Persistent vomiting
- Difficulty breathing or chest pain
- Abdominal pain
- Pain when urinating
- Convulsions or seizures
A fever can be caused by a viral or bacterial infection, heat exhaustion, certain inflammatory conditions, a cancerous tumor, or some medications and vaccinations. By itself, a fever is usually harmless, though a high fever can be miserable. Drinking plenty of fluids to help cool the body and prevent dehydration, and getting rest are some steps that may help an adult feel better.
