sam vonderheide and his friend, brian mckinney, spotted it on last month on the high sierra trail in sequoia national park. they creep up ever so slowly. nothing. no lion! uh, but look up. right over there. there s our puma. what are you supposed to do? i don t know. i don t think you re supposed to run or go away from it. reporter: park rangers say running away could trigger their instinct to chase. they decided to pitch their tents on another part of the trail this night, and had a very restless night s sleep. david wright, abc news, new york. can you imagine? i still wouldn t be sleeping. when we come back here tonight, those two important medical headlines for you. important differences when it comes to men and women and stroke. that new study out tonight. cvs accused of charging more for generic drugs and their response tonight. we re also following that deadly construction accident. the worker trapped under