The frame being hot isn't anything to really be concered about IMO. If you were at a low speed that would cause the radiator to not be cooling the bike full on, so the engine will get hot, and since its attached to the frame, it will travel on to it. Just watch the temp guage and so long as its not in the red, your fine. Also, I'd be willing to bet that you were in shorts if you were feeling it that well. If thats the case, ALWAYS WEAR PANTS! I've burned myself to many times just moving my bike around the garage in shorts, and riding in them is just asking for problems especially in a fall.
Good luck, and welcome to the board!