I drank a hibiscus tea refresher yesterday. A few minutes later I felt dizzy, vision blurred, face numb, hot&flushed. Was this an allergic reaction?

Probably allergic. But then it may also be a chemical reaction from a contaminant in the tea refresher . I recommend that you consult a B/C allergist in your area to get this checked out because the reaction can be potentially more severe the next time around. Don't delay.