Tomato help! please

Hi to all. I live in the DAllas Texas area (for the past two years, much to my dismay). This is the first year I’ve tried to garden in this climate and because we are renting, I’m doing container gardening. I’m an avid and very experienced gardener so I do know a thing or two.
However, Since I’ve never gardened in HEAT such as I’m experiencing here (97-103Ish) on a daily basis, I come to you asking for advice.
I planted 20 different tomatoes in t20-30 gal. containers. They have done beautifully until about three weeks ago when the bad heat hit. Now the bottom half of the tomato plants are turning dry and leaves brown even tho’ I water deeply on a daily basis. The top halves are staying green and still look healthy. (I don’t understand how that can happen, but what do I know) .
My tomatoes are mostly heirlooms.
SO… here’s my question, should I just ignore the plants and let them die off? (I absolutely HATE the thought of doing that), of should I continue to nurse them along hoping that when the heat spell is over, the tomatoes will revive and I may continue to have a few nice tomatoes into the fall?
Anyone who can give me some advice??
Thanks so much,

Don’t give up on those tomatoes! Trim off the lower yellow leaves for air circulation, and feed them with seaweed fertilizer to encourage more blossoms. If you have shade cloths, cover the plants when it gets super-hot. Be sure to mulch around the plants too. Lots of luck; bet you will see improvement in cooler weather.

Hi from Georgia!
This happened to my tomatoes, too. Thought they were goners and was about to pull them but they have made a turn around and are now covered with blossoms in a second run. Give it a little time and try the shade cloth as another reader said and they may surprise you.

Thanks so much for your response. I just went out and bought a shade cloth. As soon as my son gets home to help, I’ll to off the tomatoes and pray.
I look forward to a good (if small) harvest of maters.

Thanks again,