I'm on a train heading to school when I fall asleep. I woke up feeling cold yet hot at the same time around my face and neck. I felt really weak and I could barely speak a word. I also remember having a feeling of death, I thought I was going to die on that train. I was also hyperventilating. After I took off my sweater I got better shortly after. Before this happened I was very sick from violent coughs, chest pains and feeling hot all over my body. This happened twice before years ago, each time during the spring season, where my allergies start to act up. Can some one please tell me whats wrong before this happens again?