I Had To Be Medicated For A Test With Contrast

I had to be medicated for a test with contrast dye because I had a reaction to it once before. After the test on the way back home the sun was coming through the drivers window. My face started burning really bad and when I got home it was still on fire. I used cold compresses on it to cool it down. My face still get really red and it still burns. What do I need to do?