Final answer:
A fever is a higher-than-normal body temperature that helps the body fight infection by inhibiting the growth of pathogens and activating the immune system. White blood cells release chemicals called endogenous pyrogens that reset the body's thermostat, resulting in a fever.
Step-by-step explanation:
A fever is a higher-than-normal body temperature that helps the body fight infection. When the body is infected by bacteria or viruses, white blood cells release chemicals called endogenous pyrogens that reset the body's thermostat, resulting in a fever. The elevated body temperature inhibits the growth of pathogens, speeds up cellular repair processes, and allows the immune system to make more white blood cells to fight infection.