Sometimes, the overheat condition is not caused by faulty cooling system but rather a result of an engine condition.
The source of the heat that needs to be regulated is the internal combustion engine. If the combustion conditions are not right, the engine will overheat.
Take the condition of too lean air/fuel ratio or engine vacuum leak, if the oxygen content in the combustion chamber is too high, the combustion temperatures go high too.
In comparison, an oxy/acetylene torch, to increase the temperature of the flame you add more oxygen to a point where the fire does not extinguish. At the tip of the nucleus of the flame exists the highest temperature.