Fever Add to all mental checks and chaos star = + 1 stress

Does the Chaos Star comment on this card mean this is in addition to whatever chaos effect the GM decides, or a card dictates … or does it use up the chaos star?

I believe that it is like with most rolled symbols, it uses up the chaos star. Then obviously you can narrate something that causes the stress. But applying negative symbols are up to the GM, sometimes a stress might be great to throw at a player, sometimes there might be another juicy card effect. I see it as an extra option for the GM.

Obviously you could say that it is an extra stress in adition to any other chaos effect. In the end it's up to the GM.