So... heating up the sensor just melts away the dead pixels
But I do have a question: I realize that long exposures heat up the sensor and can cause damage. So I limit the real long exposures (10-50 minutes) to cold nights (usually below freezing or very close to it) to try and mitigate some of the damage to pixels and that is usually when the night sky is clear anyway. So is the cold atmospheric conditions enough to prevent the sensor from heating up and damaging the sensor?