When a cool breeze moves over a warm lake, thermal energy moves from the warm lake to the cooler breeze. This is because thermal energy always transfers from a warmer area to a cooler area. As a result, the warm surface of the lake loses heat to the cooler air above it, warming the breeze. This transfer of thermal energy is the underlying cause of the breeze's movement and temperature change. In summary, thermal energy flows from the warm lake to the cool breeze during this process.