Immediately get water on the corn. Also increase the watering interval. You can often pull a damaged vegetable plant out of trouble by increasing the watering interval. You don't necessarily have to increase the water but the interval matters. So if you were watering once a day, then you can do 2 or 3 times a day. Unless its like over 90 degrees, then I'd even do 4 times a day.
You don't have to do this forever, but just to bump them through the damaged period where its trying to heal. And the plant is getting more stress than normal now that its damaged, and more heat vulnerable. This is why you increase the watering interval temporarily also.
Now... this works very well with most vegetable plants. Except I'm not a corn expert and haven't really done corn. Where I'm at isn't suited to corn. But I've used this trick when I get heat stroke on squash plants and cucumbers, and a few others.
I can't guarantee all the plants will make it. But what do you have to lose?
You could also do some tie downs with sticks holding up the damaged stalks until they get stronger. Maybe tripods with tie downs and sticks like a swing set set up with ropes might actually work better?
I'd love to hear about the result later on how many you save.