86 Camry Overheating at Idle

[camryowner86]

Got an 86 with a little over 180000 miles, ive had it for almost two years and never had any problems until now...recently its been overheating when its just idling if i put it in neutral or park and bring up the rpms the temp gauge will drop back down to normal...it runs normal when driving around even on the freeway it doesn't overheat...also the heater does blow hot...i havent replaced anything yet just wanna get an idea where to start

please help thanx

[pmesfun]

Check level of coolant, and replace thermostat.