Buying extra time when your car is overheating

Some vehicle manufacturers might have by-passed it for their markets in the temperate regions. However, most models with climate control or A/C heating options are fitted with a heater core. Besides, providing warmth during winter months and warm up for Bikram style yogis. It can be used to cool a overheating engine but only momentary..  

Scenario: Lets say... you are racing someone to the checkered flag for honor and glory but realized that your temperature gauge is already in the reds for nobody knows how long its been there! Not sure if a hose or the radiator might blow up....

Solution: Quickly turn your A/C heater "ON". This releases about half a liter if "cooler" coolant into the overheating system, to buy you some time to reach the finish line with no hardware damage. 

In this situation, the heater core acted like a secondary radiator. As it is very small and not positioned for optimum heat transfer it is really not meant to cool the engine but to warm up the cabin. But during desperate moments like this can save you some inconvenience. Fine.. there aren't any checkered flags along the streets of Singapore to chase down.. but this method will definitely buy you enough time to not break down in a fast lane.