When the body meets extreme weather, it does not simply endure the heat or cold in isolation — it translates that stress into the language of hormones, sleep, and hydration, and the menstrual cycle listens. Across the arc of human experience, women have long noticed their bodies shifting with the seasons, and science now offers a partial explanation: it is not the temperature itself but the cascade of disruptions it unleashes that nudges ovulation and alters flow. This understanding carries a quiet but important responsibility — to distinguish between a body adapting to its environment and a b