Swiss chard and kale? Swiss chard does well for me here in the humid, hot mid Atlantic and some varieties of kale actually do well in warmer weather. It's pretty tough and one of my favorites.
Both can actually be harvested as baby salad greens, although I wouldn't suggest using the mature leaves for salad.
We sympathize; our lettuce has succumbed to the heat as well, and I'm missing it! Oh yes, balsamic vinegar does amazing things for veggies, yum!
Hope this helps.........

I'm sorry to drag up old topics, but I've just lost my zucchini, probably from overwatering. I forgot to turn off the water and it sprinkled for 10 hours on our hottest day (103 degrees).

I'm trying to keep up with the new planting, while deterring the groundhog and rabbits that keep on visiting my yard. They just won't go into that haveaheart trap. Anyway, I was thinking of planting buttercrunch lettuce. It's hot, but my wife and I both love buttercrunch, more than any other.

I don't know if it will work, but I already planted a 2nd crop of purple "green beans", straight 8 cukes and are trying red cabbage. I'm new to this 2nd crop idea. I hope they all work. Any ideas about the buttercrunch? My tomatoes are finally turning pink. It's my first year of planting mortgagelifters. Thanks for any input.
Rob in Delaware

Ahhh....here's a link I found. It may be helpful, depending on zones:
http://www.extension.iastate.edu/publications/pm534.pdf

If anyone's in the area of northern Delaware, shoot me an e-mail. Now it's time to try to fence out those varmints. I am having SOME success with an ultra high frequency alarm (solar), that shoos them away.

Rob in Delaware