This happened a couple years ago on ICE (Inter City Express) trains in Germany: https://www.spiegel.de/international/germany/the-world-from-berlin-deutsche-bah

This happened a couple years ago on ICE (Inter City Express) trains in Germany: https://www.spiegel.de/international/germany/the-world-from-berlin-deutsche-bahn-is-soft-boiling-its-customers-a-706889.html https://www.spiegel.de/international/germany/the-world-from-... > As temperatures soared to 38 degrees Celsius (100 degrees Fahrenheit), the cooling system on many ICE high-speed trains simply switched off, leaving passengers to swelter amid inside temperatures of up to 50 degrees Celsius (122 degrees Fahrenheit). > "A company that has aspirations to be a high-tech firm, but one which soft boils its customers instead of bringing them comfortably to their destination, has more than a small technical problem."