During exercise, the body primarily loses heat through evaporation of sweat, which cools the skin as it evaporates. As physical activity increases, the body temperature rises, prompting sweat production to maintain a stable internal temperature. Convection and conduction also play roles, where heat is transferred to the surrounding air or objects. Maintaining an adequate level of hydration and acclimatization to heat is crucial for effective thermoregulation and preventing heat-related illnesses during prolonged or intense exercise.