Are Braxton-Hicks supposed to...?

Hi, I'm 39 weeks, and having Braxton-hicks. Are they supposed to make me feel really lightheaded, like I'm drowning or running out of air? It doesn't feel like I can breathe, when they come, and sometimes I really can't breathe during them. And lately I've been feeling really hot and feverish all of a sudden during a 'contraction' and then it goes away when it's over. Is this normal?