What Causes Voilent Shivers Through The Body After Taking Pre-workout Supplement?

Hi, I took some pre workout supplement (1/2 recommended daily intake) this afternoon. I'm just wondering why it makes me have violent shivers every now and then lasting about a minute. It gets worse when I'm debating an argument on a Facebook post. I've taken it before at a higher dose (max daily intake) and only side effect was I became talkative. I'm 21, female, height about 160cm, weight about 53kg. I'm vegetarian but lean towards a vegan diet.