As more electric vehicles feature panoramic sunroofs, which enhance visibility but can lead to unbearable temperatures during summers, automakers are exploring new materials to help keep interiors cool.

Japanese automaker Nissan recently displayed a so-called Cool Paint developed with Chinese company Radi-Cool, a cooling technology provider.

The paint can reflect light more effectively and generate electromagnetic waves that block the sun's rays, redirecting heat away from vehicles to keep the interior cooler.

Nissan has tested the paint on vehicles operating around Tokyo's Haneda Airport, an ideal location for assessing the technology due to the large open area.

According to Nissan, the paint reduced the roof panel temperature by 12 degrees Celsius and lowered the interior temperature by 5 C.

The material is six times thicker than standard car paint, measuring 120 microns — a result of testing more than 100 samples to find the optimal formula. The research team aims to make the new paint thinner in the future, focusing on reduced weight and more color options, the automaker said.

Susumu Miura, a manager at the Nissan Research Center, said: "My dream is to create cooler cars without consuming energy," adding that this goal is crucial in the era of EVs, where air conditioning usage can significantly reduce a battery's range.

A study of Recurrent, a United States company, shows that, at 38 C, the range of electric cars could decrease by up to 31 percent, when it tested the performance of 7,500 EVs.

Toyota Motor has also been experimenting with paint that lowers cabin temperatures, mostly focusing on colors that refract the sun's rays.

Hyundai launched the Nano Cooling Film in April, which is billed as a "revolutionary vehicle window tint" that offers better interior cooling than conventional tints.

The South Korean automaker tested the Nano Cooling Film on approximately 70 vehicles in Lahore, Pakistan, where summer temperatures can exceed 50 C.Hyundai said that the film's cooling effect is optimized for higher ambient temperatures.

During testing, the Nano Cooling Film reduced the temperature near the driver's head by up to 10.9 C compared to conventional tint film. When compared to a vehicle without any window tint, the film lowered the temperature by up to 12.33 C.

In addition to the materials under development, car manufacturers have implemented measures to help vehicles cool down during the summers.

Xiaomi Auto has used silver-plated glass to enhance sun protection, saying its sedan boasts a 99.5 percent UV blocking rate and a 97.6 percent infrared blocking rate.

According to data released by Xiaomi Auto, after being exposed to direct sunlight at 38 C for 90 minutes, the interior temperature of the Xiaomi SU7 reached 59.5 C, 10 degrees lower than other models.

The Ford Mustang Mach-E features a front windshield with IRR heat-balance technology coating and a panoramic sunroof with Low-E high-efficiency heat-insulating coating.

Engineers have tested materials and components to ensure they can withstand high temperatures and strong sunlight without being deformed or damaged. The glass of the Ford SUV underwent rigorous light exposure tests, including 49 days of laboratory testing and two years of outdoor exposure, to ensure that the adhesive of the glass met high strength standards.