240d got hot yesterday
 

i just bought my first 240d day before yesterday. It is sweet! looks and rides beautiful! However, on the 250 mile trip home, the water pump/alternator belt broke and it got up to 120 or a little over. I shut her down before overheating and fixed it. It ran fine with temps where they should be the rest of the way home. Today my wife drove it on a 30 mile trip to work with no problems there and back. But, right before getting home, encountered some traffic and sat idleing for 10 min or so with the a/c on in 95 degree heat in Houston. It got to 120 again and got shut down before overheating and after cooling off drove the 3 miles home without a problem.

Is this normal for these? Or could the thermostat got locked when it got hot the first time? It has only 5k on a brand new water pump and radiator i was told from guy I bought it from and does look brand new.