The Little Book of Albert the Great ,

But in men, moisture is of an airy nature, and because heat always acts upon moisture, and this heat is natural—yet nature does nothing in vain original: "natura nihil facit frustra", as is said in the first book of On the Heavens and the World Referring to Aristotle's De Caelo, a foundational text for medieval science—and because the heat in women is always weak compared to that which is in men, and since all the nourishment in women cannot be converted into flesh, nature therefore does what is best: she provides for the body’s necessities and sends the remainder to a certain place where the menses are stored in the woman. Enough has been said concerning that matter, as it requires a greater investigation than the present task demands.

Here he raises a third doubt and solves it himself, as is clear in the text. Note that the coldest of men is warmer than the warmest of women, assuming they live in the same region and have the same digestion and intake of food, and so on. I say this pointedly, because a woman living in Ethiopia original: "Æthiopia"; used here as a geographical archetype for extreme heat who lives delicately would be warmer than a poor man in the West who always consumes the coldest of foods. But it might seem to the contrary that a woman is warmer than a man, because heat is rooted in the blood, and there is more blood in a woman than in a man—otherwise, blood would not flow daily and continuously in a woman The author likely refers to the regular cycle, though "daily" is an exaggeration or medical misunderstanding, which is not the case in a man; therefore, [she should be warmer] etc. The answer is that where there is more well-digested and well-cooked cooked: "decocto" in Latin; a medical concept where the body's internal heat "ripens" or processes nutrients and fluids blood, there is also greater heat. But this is not the case in women; therefore, etc. Note that the text says that nature does what is best. The reason is that nature is governed by an unerring intelligence original: "intelligentia non errante"; it expels the thick moisture of the woman by means of the flow. And we see the proof,