Method for evaluating how emotionally evocative a question is? I would like to measure the change in emotional state in response to a question. For example, asking the question, "What is your favorite color?" would be fairly benign; I would not expect any change in emotional state. However, I would expect a strong emotional response if I asked "What type of person do you hate?" or "Have you ever smoked marijuana?"

Ideally, we would measure this immediately after asking the question. Does anybody have any suggestions on how this can be done, or how it has been done reliably in the past? I have access to surveys and special cameras (thermal, pupil analysis, etc) if it helps.

Edit: To clarify, I'm more interested in measuring the level of emotional arousal more than measuring what specific emotion somebody is feeling. For example, I don't care if somebody is frightened or angry, just the extent to which the emotion caused arousal.
You could go with the most direct approach: After every question, ask your subjects how emotionally aroused the last question made them, for example by using a visual analogue scale. Now, this might not be suitable for your research (maybe you don't want your subjects to start to think about their own emotional state), but I think there's a danger in using advanced measurement technologies just for the heck of it. I would imagine a direct question would give your research quite high face validity for example.

However, if want to go with a more indirect approach I would recommend you check skin conductance measurements out. Here, you could for example (there are numerous examples) check out the research on precognition, which started with an experiment by Dean Radin. In these studies, you can see how skin conductance measurements vary with the content of presented pictures quite nicely (never mind if you agree with the precognition hypothesis or not).