Front windshield wiper defrost/heater, how does it work?

Windshield Wiper Cowl Cover Fit for Ford F150 2009-2014 BL3Z15022A68A BL3Z15022A69A

Some drivers have no idea about this simple trick to defrost your windshield in seconds

RV Windshield Replacement Cost: Here's What You Can Expect If You Need To Fix A Rock Chip Or Replace A Cracked Windshield

Cost to Replace a Ford F-150 Windshield: Pricing and Factors to Consider | Drivetrain Resource