What Causes Dizziness And Nausea Symptoms?

Hi... This morning outside of work, I became very dizzy and nauseaous and breathing very heavily. I also became extremely hot and sweating profusely. I made it into my office and coworkers gave me cold compresses and cold water, which helped alot. After about 12 -15 minutes, I was breathing normally again. I now notice I have red dots (like a rash) on my face. do u know what this could be from? PS: I do not have high blood pressure and not taking any heart medicine. Just thyroid meds this morning. Thank you!