you don't need water in the oil, good idle or steam in the exhaust to have bad head gaskets.
your heater core may be clogged, one hose (in) will be hot and the other hose (out) will be cold or warm. you may be able to clear it out by putting a water hose on the out side and flush it out.
there are a few things on the over heating part. fan clutch could have failed. the impeller on the water pump could have fallen off and not moving the water when your driving. there is more but its hard to say over the internet with out looking at it. you can pick up a block tester from NAPA and that will tell you if you could have bad head gaskets. it changed color with the presents of exhaust gas in the coolant.