I use a spray bottle of isopropyl rubbing alcohol to cool plastic cuts.
You just take little bites, enough feed to make a chip, but back off
frequently keeping everything near room temp. Be very patient; plastic
is an insulator of electricity and heat, so it takes a lot of time for
the heat to dissipate, thus the evaporative coolant, rather than a
flow-on coolant.

If you can get the cut started with a holesaw, you can finish it.
Withdraw, stop, and feel with your hand until you have a feel for the
frictional heat buildup. Patience! A 1:10 duty cycle is not out of the
question.

Open a window, of course.