Final answer:
The high heat of vaporization of water is responsible for sweat's cooling effect. This property requires a significant amount of energy for the phase change from liquid to vapor, thus removing heat from the body and lowering its temperature.
Step-by-step explanation:
The property of water that is most directly responsible for the ability of sweat to lower body temperature is its high heat of vaporization. When we sweat, the water on our skin requires a significant amount of energy to evaporate, which is then taken from the body, thus cooling it down. This is crucial for mammals, including humans, since it is one of the main physiological processes that help maintain homeostasis in body temperature.
While sweating, the body exploits the latent heat of evaporation, which is the energy required to change a liquid into a vapor without changing its temperature. This high energy requirement for the phase change from liquid sweat to vapor means that a significant amount of heat can be removed from the body, leading to a cooling effect. Therefore, when sweat evaporates from the skin, it takes with it heat, thus lowering the body temperature.
Other properties of water, such as cohesion and adhesion, also play important roles in biological systems but are not the primary factors in sweat-induced cooling. Similarly, while water's high specific heat also contributes to temperature regulation within the body by distributing heat, it is the high heat of vaporization that is directly responsible for cooling via sweating.