2008 Cadillac STS Owner's Manual - Page 355

{CAUTION: Turning the Intercooler System pressure cap when the engine and intercooler are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the Intercooler System pressure cap, even a little, when the engine and intercooler are hot. Notice: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mixture. {CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. {CAUTION: Adding only plain water to the cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. The vehicle's coolant warning system is set for the proper coolant mixture. With plain water or the wrong mixture, the engine could get too hot but you would not get the overheat warning. The engine could catch fire and you or others could be burned. Use a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant. 5-37