The main function of this “body clock” is to anticipated and (24) for external changes so that, for example, body temperature starts to rise (25) dawn, gearing us up for the day, and begins to fall in the early evening, winding us down for sleep.

... body temperature starts to rise around dawn (... nhiệt độ cơ thể bắt đầu tăng vào khoảng lúc bình minh).