Well, here's something for you. As you read this post, I would like you to remember that though humans are complex animalians representative of sentience and articulated thought, we're still part of the animal kingdom.

I read about [link=http://content.health.msn.com/content/article/62/71658.htm]a study[/link] in which scientists subtly introduced women to male pheromones, double-blinding to ensure women weren't turned off by realizing that it was a sweat extract being placed on the upper lip. The women reported over a period of six hours a noticeable decrease in tension and an increased in relaxation and comfort. Biologically, what was happening in their bodies was the surge of luteinized hormone production, a vital component of successful ovulation. This particular hormone surges in production anyway during the menstrual cycle, but the introduction of male pheromone helped regulate the surges during non-menstrual time as well.

Remember that male pheromones are of two different persuasions: "signalling" pheromones which may be akin to the examples specified in our animalian brethren (which would tell the female rhesus to stay within her male's territory) and "priming" pheromones which are of closer relation to the sexual attractions between Homo sapien men and women.

So, though sweat probably isn't the thing that does it for women, per se, biologically speaking, the pheromones elicit an effect.