Answer: Based on your description I am not certain what you are seeing on your peppers. It might be early signs of bacterial leaf spot or fungal infection, which thrive in hot humid conditions. It might also be tissue damage related to the cold nights last week, peppers are very susceptible to cold. You might want to consult with your local county extension to try to obtain a more specific diagnosis.
It is not necessary to cool off pepper plants on hot days. As long as the soil is evenly moist (damp like a wrung out sponge, not sopping wet or saturated) and you have the plants mulched with several inches of organic mulch, they should be fine. And, if at all possible it is better to avoid both overhead watering and evening watering on peppers, as with tomatoes, to try to prevent diseases.
Q&A Library Searching Tips