Transmission to be to hot to touch?

Hello,

If the transmission cooler is not performing as designed you could have the transmission overheat. Typically foam in the fluid is a sign on boiling point for the fluid. It will only reach that temperature if the transmission is overheats.

If there is any clog in the cooling lines it could prevent fluid flow and that can over heat the transmission.

The transmission cooler is built in the radiator.
So if there are no obvious clog in the transmission cooler lines, the radiator needs to be replaced.

Keep in mind that you only want to work on the radiator when the engine is cool.

https://www.2carpros.com/articles/how-a-radiator-works
https://www.2carpros.com/articles/how-to-replace-a-car-radiator

I have attached diagrams for your reference.

Please let me know of any questions.
Thank you.