Final answer:
The last event of a fever is called defervescence, occurring during the period of decline, marked by the breaking of a fever and the body cooling off through heat release and sweating.
Step-by-step explanation:
The last event of a fever is known as defervescence. This happens during the period of decline, which is one of the stages of a disease process. After the period of illness, where symptoms are most severe, the period of decline involves a decrease in pathogen particles and the subsiding of signs and symptoms. Defervescence is characterized by the breaking of the fever where the body's hypothalamus stimulates vasodilation leading to a release of heat and sweating, thereby cooling the body. This process marks the transition towards recovery, although patients may still be vulnerable to secondary infections.