It is 98.6 degrees Fahrenheit and up. It is the same temperature as the rest of your body. It is usually closed off from the outside unless something is inserted into it, and what little air that is in it gets hot over time, not being able to be cooled and raising the temperature to 100+ degrees. It gets hotter during sex because your core temperature will rise as hormones and enzymes flow, as well as the blood-flow. Upon orgasm, the temperature can raise higher because of contractions. Know how when you exercise that your muscles (or even your whole body) gets hot? It's the same thing. A woman getting "hot" isn't an exaggeration, it's a fact. It really does get hot in there. It can be hot enough that it can make a guy want to back out of you because the head of the penis is sensitive to heat, and it can even cause him to go soft. The temperature differs from person-to-person. I say you shouldn't worry though. If ya wanna know how hot it is; try putting an ice cube at the opening. If it melts; you're hot. Just kidding... Don't really try that, as the cold temperature and ice may cause tissue damage at the vaginal opening. Hope this helps. :)

never heard of that

No!

Not a woman but I can say when my wife, now ex, was on her period and we had sex she felt much warmer than normal and also smoother inside.