Car interior heat can become life‑threatening within minutes – risks and cooling measures

Studies show that a vehicle left in direct sunlight can heat up far faster than the outside temperature. A 2010 University of Georgia experiment found interior temperatures rising 4 °C in five minutes, 7 °C in ten minutes, 16 °C in thirty minutes and 26 °C after an hour compared with ambient air. Recent ADAC tests recorded interior air above 60 °C and surface temperatures on the steering wheel and dashboard exceeding 70 °C, creating burn hazards.

The rapid temperature increase poses serious danger to children, the elderly and pets. Children regulate heat poorly, sweat less and need more fluids; seniors often have reduced thirst perception. A fatal case in Bavaria in June 2026 involved a 20‑month‑old left unattended in a parked car. Dogs can suffer heat‑stroke above 40 °C, with mortality rates of 50‑60 %.

Mitigation measures include venting the cabin before entry using a remote‑key function that opens all windows, parking in shade, using reflective sun‑shades or a full‑cover “half‑garage” tarp to lower interior temperature by about 10 °C, and applying reflective films to windshields. Light‑colored vehicle paint and smaller glass areas also help keep interiors cooler. The ADAC recommends keeping children out of parked cars entirely, using sunshades, and ensuring adequate hydration.