Target those deep blowdowns ANYTIME you can find one
Get a weedless jghead and some plastic bodies (tubes/grubs/critters) and work all over that blowdown ... above it and down in it !!!
Sometimes lakes stratify in Summer, creating a thermocline ... water is cooler below it, but oxygen levels are too low to sustain a fish for long. Find any kind of structure/cover that offers shade, and parts of it extend above that thermocline line ... fish from thermocline depth, up to just below whatever depth your bait disappears from sight, right on that cover.
Flats with stumps, humps with stumps, patches of standing trees, bridge pillers ... anything with the capacity to create shade, that's in water depth above the thermocline level ... has the capacity to hold fish. Covered docks are also a possiblity, even in relatively shallow water. And they may be best at the midday timeframe.
White Crappie will tolerate fairly warm water, given the oxygen content is suitable. Grass beds and water plants will give off some oxygen, too ... so having them in the area can be a plus (as long as they don't occupy all the space in the water column).
... luck2ya ... cp