I'm not the kind of actor that can go completely cold into an emotional scene. I have to transport myself emotionally by whatever means possible, and that basically means you carry the situation with you all week, all episode or all day beforehand.
My only hesitation after 'Law & Order' was that I didn't want to be in a super dry procedural like that. I found that satisfying, but very tough because every episode was kind of the same. It just is with that show.