You should go to the hospital for a fever in the following situations: For children:
- A fever of 105°F (40.5°C) or higher at any age is a medical emergency requiring immediate hospital visit.
- For babies under 3 months old with a fever above 100.4°F (38°C), go to the hospital immediately.
- For children 3 months to 3 years, a fever over 102.2°F (39°C) lasting more than 24 hours or accompanied by symptoms like difficulty breathing, persistent vomiting, seizures, stiff neck, rash, or inability to drink fluids requires emergency care.
- If a child has a fever and symptoms like difficulty waking up, nonstop inconsolable crying, rapid/difficult breathing, rash, inability to urinate, severe headache, or seizure, go to the ER promptly.
For adults:
- A fever of 103°F (39.4°C) or higher especially with symptoms such as confusion, difficulty breathing, loss of consciousness, severe pain, seizure, or painful urination is reason to seek emergency care.
- If fever lasts more than 3 days, or spikes above 103°F with worsening symptoms.
- For immunocompromised adults or those over age 65, a fever of 101°F (38.3°C) or higher should prompt calling a doctor.
- Fever of 105°F (40.6°C) or higher requires immediate medical attention.
In general, also seek hospital care if fever is accompanied by severe headache, stiff neck, rash, difficulty breathing, persistent vomiting, dehydration, or neurological symptoms like confusion or seizures.