Which of the following temperatures is indicative of a fever?

Fever is generally defined as a temporary increase in body temperature, often due to an illness. The commonly accepted threshold for fever in adults is typically around 100.4°F (38°C) or higher. The correct answer indicates a temperature of 101.5°F (38.3°C), which is well above the threshold necessary to classify as a fever.

This higher temperature signifies the body's immune response to infection or other inflammatory processes. While other temperatures listed might be elevated, they do not meet the standard criteria for fever. For instance, 100.4°F is exactly on the threshold but does not exceed it, and temperatures like 99.5°F and 98.6°F are still within the normal range for body temperature. Therefore, the identification of 101.5°F as indicative of fever correctly aligns with medical definitions used in clinical practice.