View Here : What To Do If Car Overheats
do not top up an overheated engine with cold water, wait until the engine has cooled enough to touch, otherwise it could be damaged. Tips: In winter one of the tell tale signs a car is running without enough cooling water is when the heater starts to blow cold air into the car instead of hot.
Engines typically overheat because the coolant’s low, so topping it off will usually solve the problem. Failing that, water will also temporarily do the trick. Plus, that water could be a lifesaver on long, sweltering summer drives.