2005 GMC Safari Owner's Manual - Page 239

If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about 10 minutes. If the warning does not come back on, you can drive normally. If the warning continues and you have not stopped, pull over, stop, and park your vehicle right away. If there is still no sign of steam, you can push down the accelerator until the engine speed is about twice as fast as normal idle speed for at least three minutes while you are parked. If you still have the warning, turn off the engine and get everyone out of the vehicle until it cools down. You may decide not to lift the hood but to get service help right away. Cooling System When you decide it is safe to lift the hood, here is what you will see: A. Coolant Recovery Tank B. Radiator Pressure Cap C. Engine Cooling Fan If the coolant inside the coolant recovery tank is boiling, do not do anything else until it cools down. The vehicle should be parked on a level surface. 5-31