Hyundai says it’s developed a window-tinting film that can cool interior vehicle temperatures by dozens of degrees.

The Nano Cooling Film blocks external heat energy and transfers internal radiant heat outside the vehicle, cutting internal temperatures near the driver’s head by about 52 degrees compared to conventional tint films and up to 54 degrees compared to no tinting, the South Korean automaker said.

In a new “Made Cooler By Hyundai” ad campaign, Hyundai applied the film to 70 customer vehicles in Lahore, Pakistan, where it said summer temperatures can climb to more than 120 degrees.

It said the film both exceeds conventional tint films’ effectiveness and is transparent so it doesn’t obstruct occupants’ view.

The film contains a three-layer heat-transferring nanostructure that selectively block or emit specific solar heat wavelengths and that it anticipates to be more effective in hot, dry climates like Lahore’s, where it said the technology’s effect is optimized.

Hyundai, which said it plans to mass-produce the film in the future, said the substance can be applied along with conventional tint films for enhanced cooling.

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