Tammons offers some good advice. I will add that one summer 6 years ago I did an overnighter here in N Ga during late July when the temps during the day were around 100 and it was barely getting down to 80 at night. I didn't take a bit of any kind of under insulation with me, only a silk bag liner and an emergency blanket. Naturally, we had a monster of a severe storm that afternoon, and the temps at about 3500' dropped into the upper 50's that night. Coldest night I have ever spent. If I had had a ground cloth and a pad, I would have gone to ground and used my HH as a bivy. After that experience, I always carry some sort of poncho/garbage bags as Tammons mentions above.
Hiking & Hanging is therapy, and much cheaper than medication in the long run. Carry on.