Oppo, help me diagnose a weird brake problem/issue, please!

For a few weeks now, my brakes have been giving me a slight shudder in the steering wheel, just as if the rotors were a little warped. No biggie, I knew that they were nearing the end of their lifespan anyways. It just wasn't really consistent. Sometimes a little heavier, at other times barely if at all noticeable.

Today, I realized that it is really terrible when the brakes are cold. As soon as they get up to a certain temperature it fades away until it is gone. As soon as the brakes cool down it comes back, like on a long trip on the Autobahn where you don't have to use the brakes for a very long time.

My armchair diagnosis would be that the rotors are a little warped when cold, but straighten out when they get warm, but is that even a thing? I'v never heard of such a phenomenon.

What do you say?

Also: My car is like a race car now! Brakes have to be kept warm to work perfectly.