Be thankful your installing plumber di the RIGHT THING.
If your vent terminal was cold your sewer vapor would freeze on the internal pipe and cause sewer gases to stay in your home PLUS rendering your plumbing fixtures just about useless.
The little bit of heat going up this vent pipe is prevent “HOARFROST” vent closure.
What you could do is contact a roofing contractor and have them install a “pitch pocket” made of stainless steel or copper Or cast Iron ( NEVER PLASTIC CRAP) around this vent pipe and fill the pitch pocket with bitumen like flashing cement.
Your very lucky to have a working vent system.
Here you thought we only know plummmin huh?