I Have Had Two Episodes, Similar In Nature. I Felt

I have had two episodes, similar in nature. I felt a hot flushed sensation in my face, it turned red and felt warm to touch. My heart rate increased to 135 while resting, I passed out, and then vomitted. I was sent to ER and upon arrival I had diarrhea. All tests (chest xray, EKG, blood work for thyroid and heart attack) came back normal. I was sent for food allergy testing and all results came back normal.