Do Fish Experience Cold, or Simply Temperature Change?

I'm reading An Immense World by Ed Yung and it said this:

"...Fish seem to lack TRBM8 all together, and most them can tolerate temperatures close to freezing..... They have no idea what it's like to be cold."

If I understand that correctly it means they recognize temperature, but not discomfort from cold temperatures.

That doesn't make sense to me.

Surely fish have a temp preference??

People put heaters in betta tanks for that reason right?

Note: I am not a marinebiologist