What physiological change occurs during sweating?

When the body sweats, it primarily serves as a mechanism for thermoregulation, which is crucial in maintaining a stable body temperature. The physiological change that occurs during sweating involves the evaporation of sweat from the skin's surface. This process absorbs heat from the body, leading to a cooling effect. As the sweat evaporates, it takes heat with it, thus reducing the overall temperature of the skin and the underlying tissues. This is essential during physical exertion or in hot environments, as it helps prevent overheating and maintains optimal functioning of the body.

In contrast, the other options do not accurately reflect the physiological response to sweating. Body temperature rising would occur in the absence of sweating, fat loss is not a direct result of sweating itself but rather a result of overall energy expenditure, and a decrease in metabolic rate typically occurs when the body is at rest rather than during an active cooling process like sweating. Therefore, the primary physiological change associated with sweating is body cooling, making it the correct answer.