The guy's a freak, but it's probably his mother's fault; most weird behaviour involving sexuality or toilet training is down to the major parent.
As for the body temperature thing, the increase in body temperature is not what makes women horny; the expression 'feeling hot', is just an expression. Lots of women get horny round ovulation, but the heat is a by-product, it's the horny-moans that increase desire.
I slept with a girl once who had on knickers (panties to you Americans), a bra AND a body. It was a little strange, like she was scared they'd get out or something...
As for women's sexual desire not showing, where have you been?
*Dilated pupils, increased blink rate
*Increased respiration
*Moistening of lips with tounge
*Nipple erection
*Facial reddening
*'Unneccesary' body contact with object of desire
*Greater tendancy for direct eye contact with object of desire
*'Fidgety' behaviour compared to normal
*Change in vocal tone compared to normal, greater tendancy to laugh at perceived funniness of object of desire
*Possible complaints of tummy aches or cramps (a sign of very high horniness unless it's menstural cramping)
*Body language changes
Obviously, other things can cause any of these, but the more of these signs you observe, the greater liklihood there is of being right. Guys are easier, sure, they have erections and drool, but women are not unreadable.
Some girls DO make the 'job' easier, like a dear South African friend of mine who was wont to say things like "I'm horny as hell, fancy some?"
People living in glass paradigms shouldn't throw stones...