We protect some of our plants from cold; why not protect them a bit from heat. Sure, we can’t change the ambient air temperature on a 90 degree day, but we can keep our vegetables shaded on the hottest days of the summer with reasonable results.
The vegetable garden can start doing some funny things during a heat wave. When temperatures start to raise into the upper 80s and 90s, many vegetables drop flowers before pollination and fruit set and stop blooming. Beans, tomatoes and eggplant do like it hot, but there is a threshold of tolerance to heat.