I've been learning more about corns also. Like, this website says hot spot of 88-92, but then some people said that will cook them.
If I'm correct, ambient can be 78-80 with a hot spot of 80-84.
You could direct a small fan at them if you think there tubs are getting too hot.
I'm not sure if Corns need a hot spot, or if they can just do good with a single ambient temp of 80-82.
I'm sure someone will chime in.