Trucks with a 6.7L Cummins engine have a block heater built in, so if you live in an extremely cold climate, you'll want to know where it's located.

If you live in a region with below freezing temps, you may have heard of engine block heaters. Here's what they are, the different types, and how they work.

A 1972 University of Saskatchewan study found that a block heater will get an engine about as warm as it will ever get after about four hours.

In these extreme temperatures it'd be wise to use it." A block heater works by keeping a constant, low heat heat on the engine block and coolants.