The thermostat is suspect. It's possible it's not opening under low engine idle speeds/pressures. When you're moving the airflow helps keep the engine cooler too, but start with the T-stat they're real cheap and easy to R&R.
Other possible causes could be inadequate coolant/reservoir level, (also easy to correct), fan clutch lock-up, water-pump lock up.
-Do Not- let the temperature get redline under any circumstances, if it goes about 230 again it didn't fix it, shut it down immediately. Even the slightest amount of over-temp can wear the engine components out.