Heavy-duty trucks emit >25% of the CO₂ of the European road transport sector despite representing ≈2.5% of its fleet. Escalating temperatures associated to global warming will increase the use of air-conditioning (AC) in heavy-duty trucks, further raising their fuel consumption and emissions. Thus, sustainable solutions are needed to reduce the thermal loads affecting the truck cabins, to minimize the need for AC and decrease the sector’s costs and environmental footprint. We assessed the economic and environmental impact of AC use in the European heavy-duty transportation fleet, for realistic environmental conditions throughout the year, across the different European regions. Potential reductions were estimated for various changes in the optical properties of the cabin external paints and glazing elements (windshield and side-windows). The use of high-reflectivity paints in the cabin external surfaces and low-transmissivity glazing can reduce fuel costs by ≈€195 million/year across Europe (i.e., ≈0.1% of the total fuel costs of the European heavy-duty fleet), and decrease CO₂ emissions by 1% of the reduction target set for 2025. These potential reductions highlight the importance of engaging with transportation stakeholders (e.g., workers unions, vehicle manufacturers, policymakers, and regulating bodies), to raise awareness about the potential benefits for the European transportation sector and the environment, and to promote the necessary adaptation in the transportation fleets.