I foolishly tried to co-germinate some lettuce and tomatoes in a flat with peppers that was running about 85F.

The peppers seem to be doing fine but the lettuce and tomatoes have been spotty. I understand some plants have a maximum germination temperature.

But if I cool this flat off, will the cooler-loving plants then germinate? Or does heat activate a biological mechanism that will prevent germination permanently such that I should start over with new seeds?

Thanks, I hope this is clear.