There is a problem removing the heat out of the engine. First check the coolant level. If the level is low, add more water (after the engine has cooled down). But where did the coolant go? If the
oil has any white or brown color to it, don’t start the engine and call your mechanic. Hopefully the coolant leaked out the overflow or somewhere besides the engine
oil. Don’t start the engine until you have found the problem and have fixed it. The water temp should not go much over 100 C.