How is fever medically defined?

Fever is medically defined as a body temperature that exceeds the normal range, typically considered to be over 100.4 degrees Fahrenheit (38 degrees Celsius). This increase in temperature is usually a response to infection or illness, as it assists the immune system in fighting off pathogens. The body's set point for temperature regulation is raised, leading to an increase in overall body temperature. This definition emphasizes that fever is an elevated state rather than a normal or decreased condition, highlighting its role as an indicator of underlying health issues.

Understanding the normal temperature range helps clinicians assess when a patient's condition may indicate a fever and the subsequent need for further evaluation or treatment. The other options do not correctly capture this critical aspect of fever; therefore, identifying that fever represents a body temperature above the usual range is essential for accurate clinical assessment and management.