I'm post menopausal so don't get hot flushes any more but in social situations if I crack and have a glass or two of wine I get very red faced. Equally with over exertion I go very red faced.
That could be an alcohol flush, or a reaction to sulfites which most wines contain, as a preservative.
Lots of other foods and beverages contain sulfites, like dried fruit, coconut, many processed products, etc.(Sulfites are a trigger for some asthmatics too.)
Exercise does cause mast cells to degranulate, so it's definitely worth looking into further.