Heating a rotor in itself wont warp them. The warp comes from heating them and then holding the pad againts the rotor when you arent moving.
A good example is coming down a big hill, you apply the brakes for a decent amount of time to keep from gaining too much speed. Once at the bottom, you stop at a red light and just hold the brakes. The rotor starts cooling off everywhere except where the pad is up against the rotor, that stays hotter and warps the rotor.
I have always been "hard" on my brakes in all my cars and have yet to warp any rotor, stock or not. Its mostly in how you drive. ymmv