It's not the heat that's killing the cuke plants but the root knot nematodes are. When the leaves started getting pale despite regular fertilizing and then turning light yellow, I knew the 'todes were at work. Sure enough, when the plants were pulled yesterday the roots were all knotted up.
I have a 4' wide trellis in another part of the garden with a a young cuke plant on it that has three small cukes set on it. They'll be ready in a few more days. Meanwhile, I started two more plants from seed and will set up a trellis for them. The pickling is done but it's always nice to have for fresh eating.