-keep the plants irrigated, they are transpiring a lot with the heat. all that water is pulled up through the plants, and berries.
-berries are 90% water, so as they increase in size this week, a lot of that size is due to water uptake
-harvest as early in the day as possible, to minimize soft and hot fruit.
-consider going to a night harvest? Its been done in grapes and apples.
Heres how they do it in apples an article from good fruit grower. It might not work for you now, but something to consider.