Block heater is an interior car accessory that can be attached to the backside of rear view mirror of the car. It is designed to prevent forming of frost and fog on mirror in subzero or rainy weather. Clearing of frost and fogging can help drivers to have a wider view of things behind the vehicle even in extremely cold weather conditions. The amount of electric power consumption is automatically controlled by the film heater in accordance with the temperature change of mirror facet, which in turn reduces the electric consumption.

Block heaters can also be defined as an electrical device used to heat engine of the car in winters. They are generally attached to car's engine. An engine block heater is used to warm the car engine when it is not working. Engine block heater is provided with a heating coil that goes into the engine block by replacing a freeze plug.

Block heaters usually run from an external electric source.

Advantage of Block Heaters:
There are several advantages of using block heater in winters. Some of them include:

• Prevents forming of frost and fogging on the rear view mirror in winters and rainy weather.
• Helps to improve air quality and fuel economy.
• Warms up engine and lubricants thereby helping smooth start of vehicles during cold weather.
• Saves fuel and reduce wear and tear on the engine.
• Protects environment by reducing emission of greenhouse gases.

Maintenance of Block Heaters:

• Proper care and maintenance of block heater is very important to assure smooth start of engine in winters.
• It is also important to keep the rear mirror of the car fog and frost free for clear vision of vehicles behind it.
• Hence, periodical maintenance of block heater is essential to avoid hassles in driving during winter.