pontiac sunfire engine question?

[Tyler]

i have a 96 sunfire with 124,000 miles. about 1500 miles ago i changed the head and gasket. The oil has been replaced less than 1000 miles ago, and just recently it started to get hot. I was getting good heat from the heater, but the car seemed to get hot. im thinking its the thermostat, but im not really sure...what do you guys think?

 

[melsg5]

assuming you are not losing any coolant, it's a good place to start