It's like a feeling of congestion, flushes of heat, often associated with anxiety. The sensation may be localized or general.

Once I was at a lecture and I wanted to ask a question of the speaker. As soon as the microphone was in my hand, I think I almost lost consciousness. I did ask my question but couldn't physically hear the answer because my ears were ringing, my heart was pounding, my face was flushed. I just nodded my head at what I hoped were appropriate intervals. It took several minutes for the effects to wear off and to stop shaking.

So if your patient reports this kind of reaction under stress it could be an avenue worth exploring, or it may be a confirmatory sign of a particular remedy.

Chris