You are correct and I misremembered it. “The Big Freeze” and “Heat Death” are the same thing. Thats when everything expands until there is no more heat.

If someone knows the correct terms for what I am talking about please let me know. Let me explain further.

What I am talking about is the opposite of heat death, which is somehow in my mind at a hot death? Basically, where everything goes back to one singularity instead of expanding forever.