If you know a frost is coming, maybe using caterpillar tunnels and row cover to try to save the plants. Row cover on first, tunnel over top of all.
If you are going to get those really high temps, planning ahead to find and pile on the mulch may help to some extent. I know my garden did as well as possible in the drought here in Mass this year because I was able to mulch no less than 4" deep everywhere.
I've seen other gardeners here make arches of saplings and string and run the sprawly guys (squash, cukes, etc) up and over them for shade for plantings under the arches.
Be careful using grass clippings that are green. They heat up and can damage plants.