Regularly look at the radiator. Allow your car to operate for the bit after which change it off and pop open the hood. In case the car is running, usually do not open the radiator.
https://www.youtube.com/watch?v=1aPd8ZemaIo
http://vidmax.com/video/107954-LED-Outfitters-Are-You-Having-Car-Problems-Try-These-Pointers