cary,
I don't have any where near as much experience as a 'taper' as many, if not most on this board but I've lived my whole life around pro audio and in my experience you should have no fear of running your c4's for eight hours of 100 degree festie sunshine. If your mics were glossy black and large diaphram I might hesitate, but really relax have a good time and +T for calling yourself a n00b ( me too )
Kris