Katniss, was selfless in the games, although this is a positive trait, how did it negatively affect her?

Katniss leaves herself vulnerable. She is taking care of other tributes, like Peeta and Rue, at the risk of her own safety. She even threatens to kill herself if they do not let Peeta live as well. This can be looked at as negative but it is also what makes Katniss so passionate and strong.