Severe illness can cause extremely high temperatures in adults that can be life threatening. A high-grade fever from a rectal measurement is typically 104.1–106.0°F (40–41.1°C). When certain pathogens ...

You may need to get plenty of rest and drink fluids to help your body heal. But if you have a high or long-lasting fever longer than 3 days, you may need urgent medical care. A fever is a common side ...

The temperature that constitutes a fever varies by age and the method of measuring it. Generally, doctors consider any body temperature over 100.4°F (38°C) a fever. A fever is a body temperature that ...