What is the temperature of genitalia when aroused/during sex? Is it different for men and women? Doing a bit of research for an idea I have (and no, I'm not going to be shoving thermometers down people's pants ).
C'mon, this place is filled with nerds (and Gnerds). Someone must know the answer to this question! (As for me, I overslept the genital temperature-taking class.)
It won't be significantly warmer than the rest of your body - I expect it'd be about the same temperature as under your armpit. Testicles will be a bit colder.
The temperature increases with volume and blood flow and distance to body core (more heat gets transferred from the core body to the body part with blood flow and volume creates heat inertia) and decreases with surface (surfaces lose heat by radiation, evaporation, evaporation from sweat glands and convective cooling, so the more surface there is, the more heat is lost). So a vagina will be quite hot (small outside surface) and even a bit hotter during arousal (more blood flow). Balls and a flaccid penis are quite cool (high surface/volume), balls especially are quite cool, because it doesn't work well under normal body temperature. Erect penises are probably hotter (more blood, higher volume/surface). I think armpit will be comparable with vaginas. PS. Bigger objects have a lower surface/volume ratio. This may seem a bit strange, but here's an example: If you slice an apple in two, two new surfaces are created, so the surface/volume ratio increases.