I thought i had replied to this earlier but something must of went
awry.
I know there's the chapter on it in Larry Coburn's book, which overall
is a very useful resource for MD streams,  but i think he included
Paint Branch in there as more of a discussion piece than a
recommendation on a good stream to hit.
Speaking of hot... I haven't heard of any fish being caught since the
drought year of 2007 and with the heat last summer, I wouldn't be
surprised if the small population was almost completely destroyed.
Even during a cool summer the temps still get over 70 for prolonged
periods, making survival difficult even for the hardiest of brown
trout.  With the amount of heat we had combined w/ extremely low
flows, I would be very surprised if you find anything beyond sunfish,
suckers and eels,
interested to hear how it goes.
good luck and be safe.
/brendan