Auto Parts: Overheating, 2000 chevy cavalier, dexcool coolant

Question
Hello..I own a 2000 Chevy Cavalier that has about 63K miles on it. Lately the temp is constantly one bar over the normal midway point on the temp gauge. It's been that way for a while, but lately it is going further over than that (especially when I put the heat on). What could be causing this? Should I get the radiator flushed? It has the 90K mile guaranteed red Dexcool coolant in there, so I thought it'd be fine now. What should I look for?
Thanks,
Neal

Answer
Check your oil levels, and coolant levels you might have a slow leak. Its always good to flush the radiator though. This gauge is connected to your thermostat. Thermostat should give you accurate reading of temp...I would start with checking fluid levels. Good Luck!