I think it's Hypoglycemia-related. I will know for sure in the next few months when I endure a strict hypoglycemic diet. A lot of people have this flushing. It's interesting that we have it in the same situations. Also when the temperature of the room is warm. It's always okay outdoors. Were you an athlete?
Another thing that helps but is a little more difficult is changing your perception of perceived stress (I think the flushing is an adrenaline response due to a perceived stressful situation combined with low blood sugar). There is a book called "Conversations With God" that is not religious, but spiritual, and helps.
If someone finds the answer before I do please let me know.