Don't treat a Prius like any other car when it comes to a cooling issue
IF THE CHECK ENGINE LIGHT comes on, or the TEMP GAUGE starts showing the car is overheating - STOP IMMEDIATELY and DON'T drive it ANY MORE!
PRIUS' does not use a mechanical water pump - it's an ELECTRIC pump - and it it, or the Thermostat, goes out there is NO water circulating thru the engine AT ALL! Meaning a very., very short time to a Blown Head Gasket!
READ the Owners Manual,. very carefully, to learn all the other "quirks" in the car design.
IF you maintain the vehicle properly, it's a fantastic, economical, comfortable machine. Just stay on top of the maintenance.