Heat is only one factor, other important factors include sunlight and water clarity. As I understand it you might try to find color water - by finding shaded areas such as underneath docks and vegetaion. Lure choices would include lures that you can skip underneath docks and penetrate matted weeds - or scoot across the surface of them...if those aren't working (or available) carolina rigged worms fished along structure and deep diving crankbaits may work. I like the Rat-L-Trap myself - but I usually fish smaller lakes/ponds that don't get very deep.
I wouldnt go with the C rig stuff, I would stick with some shallow fishing, because fish always are shallow especially after rain and in the morning, and use a drop shot randomly pitching outside of weedlines. Random pitching with that drop shot has caught me a TON of fish when I got stumped days in a row. Drop shot a senko
I use a lot of Carolina rigs when the temps rise. I also love to fish soft jerkbaits in hot water. I've caught fish on flukes, walking the dog beneath the surface, in 102 degree water lol Granted they weren't big but they 'kept' and sure were a load of fun!