Thermal Camera Reveals: Window Seats in AC-Free Trams Hit Over 50°C

Using a thermal imaging camera, researchers in Prague compared just how hot tram interiors get in summer weather, with and without air conditioning. The experiment was carried out last week, when the air temperature in the shade climbed to 34°C.

The hottest spot turned out to be the seat by the window facing the sun. In a tram without air conditioning, the thermal camera recorded 51.5°C there, with the seat itself reaching 46.7°C and the floor 45.4°C. In an air-conditioned tram, the same spots were noticeably cooler: 39.3°C, 34.7°C and 35.1°C respectively.

Why the Camera "Doesn't See" Metal

The footage was shot by thermographer Jaroslav Němec. According to him, the device "shows a world people can't see on their own" — but the technology has its limits. Clean metal surfaces, such as the handrails on a tram, emit almost no heat of their own, and whatever isn't emitted gets replaced by reflection instead. "That makes measurement extremely tricky, if not impossible altogether," the specialist explained.

Dark Car Bodies Heat Up Faster

The team also tested how surface color affects heating outside public transport, comparing two cars parked next to each other. The thermal camera showed that body color makes a significant difference: the gap between a white car and a black or dark-colored one can reach 10–15°C on the surface, Němec noted.

Around Prague, based on reporting by novinky.cz