Re: Will I kill 'em?
Good advice given here already regarding carrying a thermometer... great idea once the flows drop off and the temp's heat up. It would probably surprise some that many of the "storied" trout streams in the East regularly experience marginal water temp's during the summer and some in the Catskills (I think) are still closed in the summer, or at least portions of them. It wasn't all that long ago that PA closed it's trout streams over the summer.
Having said that, native brookies can only survive in clean, cold water and any stream that experiences marginal conditions described here probably wouldn't hold brook trout.
"We fish for pleasure; I for mine, you for yours." -James Leisenring