Final answer:
Exercising vigorously and having an infection can both result in an elevated body temperature. While exercise increases body temperature through metabolic activity and muscular work, an infection prompts the immune system to raise the body's temperature to combat pathogens.
Step-by-step explanation:
When a person is exercising vigorously, their body temperature rises due to increased metabolic activity and muscular work. This elevation in temperature is a result of the body's increased energy production to fuel the physical activity. On the other hand, when someone has an infection, their elevated temperature is a response of the immune system to fight off pathogens. In both cases, an elevated temperature helps the body combat the underlying issue.