Science Fact: Women respond to almost any physical contact with a rise in skin temperature, and more so if it's with a guy (but they don't realize it).
Explanation: We've already covered how guys respond when they interact with a girl; their eyes turn into big stupid cartoon hearts, and when asked "What is the capital of Alaska," they are respond that it is girls. This may lead you to conclude that life is terrible and unfair, because women clearly have the upper hand in all these social situations. But it turns out that women have a similar (though not identical) reaction; in response to contact, they get physically hotter without realizing it (often to the point of blushing), and this especially happens if the dude touching them is a dude.
The Science: Some British researchers set up a study in which female participants were interacting with an experimenter who had a totally fictional but research-related reason to touch them ("I need to calibrate this science machine," we hope he said, while mashing a graphing calculator in a woman's face). In reality, this was just a pretext for physical contact, and the actual science machine was a thermal imaging camera that was recording the participants' facial and body temperature. Experimenters would either touch them at a non-personal location (e.g. the hands) or a personal one (e.g. the face) and hopefully this concludes the only talk of hidden cameras and personal locations in the history of SparkNotes.
Anyway, this was all distinctly non-flirty touching, by a science person, with women who had volunteered for a study, but their reactions were pretty noticeable. Their skin temperature increased around a fifth of a degree Fahrenheit, on average, with the smallest increase coming from the boringest of interactions (another woman touching their hands), which we will grant doesn't sound like much. But when a man touched a participant's face or chest (NOT LIKE THAT UGH), the increase was three times that, and in some cases it was almost two degrees. This does sound like much, at least to the researchers, who said it's the kind of increase you get with "an explicit emotional stressor," like embarrassment or rattlesnakes.
So What Should I Do About It?
The big point to take away from this is that women aren't totally unfazed by the whole social interaction thing; it's just that way they're fazed is different than it is for guys. Men are walking around thinking "girls girls girls girls girls," and when they see a girl, they go "PTTHBT," spitting out their coffee in lust, and are like "OH MY GOD, IS THAT A GIRL." They get stupid and can't help it. Women are less likely to fixate that way, but their bodies respond to even ordinary scenarios with a temperature increase we usually associate with sexy shenanigans. (Furthermore, only about 25% of the women in the study were aware of the temperature increases; most had no idea.)
The other point to take away from this is that you have to be careful not to read sexiness into a scenario where there is no sexiness at all. If a researcher touches a girl's face and her skin flushes, in all likelihood, the hidden meaning to this reaction is "the temperature of my face has increased;" of course, guys are always likely to misread this as "I am asking you on an immediate date to the inside of my pants."