2001 VW pat "STOP, check engine coolant" light on dash.. help?

i was on the highway when i noticed my engine was getting a little hot.. hotter then it ever has been so i drove 25 miles back home and turned my car off. started it up about an hour later and it seemed like it was normal at 190 degrees but after about 5 minutes of driving it was basically as hot as it woul go on the meter so i stopped for a second and then on my dash it said "STOP check engine coolant". and yes its topped off. the next day i started it up and it took about 3 mintues to overheat. water-pump? therm? so if any1 can comment on what they think is wrong with it i'd appreciate it.