Overview
A fever is a temporary increase in body temperature, usually in response to infection. Normal body temperature averages 98.6°F (37°C), but can vary. A fever is generally considered 100.4°F (38°C) or higher.
When fever is helpful
Fever is actually a sign your immune system is fighting infection. Moderate fevers can help your body fight off pathogens more effectively by stimulating immune cell activity and creating an environment hostile to viruses and bacteria.
Self-care tips
For adults
- Stay hydrated: water, broth, electrolyte drinks
- Rest: your body needs energy to fight infection
- Dress lightly: don't bundle up
- Cool compresses: on forehead and wrists
- Over-the-counter medications: acetaminophen or ibuprofen as directed
- Monitor temperature: check every few hours
For children
- Follow pediatric dosing guidelines carefully
- Never give aspirin to children (risk of Reye's syndrome)
- Keep the child comfortable and hydrated
- Sponge bath with lukewarm (not cold) water if needed
When to seek care
Adults: see a doctor if
- Temperature exceeds 103°F (39.4°C)
- Fever lasts more than 3 days
- Accompanied by severe headache, stiff neck, or confusion
- Rash develops alongside fever
- Difficulty breathing
- Persistent vomiting
Children: get care right away if
- Under 3 months with any fever (100.4°F+)
- 3-6 months with fever above 102°F
- Any age with fever above 104°F
- Fever with seizure, lethargy, or rash
Fever is usually a healthy immune response. Focus on comfort and hydration, and know when professional care is needed.
Common questions
At what temperature should I go to the hospital?
Adults should seek emergency care for temperatures over 103°F (39.4°C) with severe symptoms. Children under 3 months need care for any fever of 100.4°F or higher.
Should I let a fever run its course?
Mild to moderate fevers (under 102°F in adults) can be left untreated as they help fight infection. Treat if uncomfortable or if temperature climbs above 102°F.
Is it safe to take a bath with a fever?
A lukewarm bath can help reduce fever. Avoid cold baths or ice baths, as they can cause shivering which raises body temperature.
Sources and further reading
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MySymptom gives general health information. It is not medical advice and can't tell you for sure what is causing your symptoms. If you are worried, contact a clinician. In an emergency, call your local emergency number. How answers work