Astronomers using ALMA have detected the earliest hot galaxy cluster atmosphere ever observed, revealing a massive reservoir of superheated gas in the infant cluster SPT2349-56 just 1.4 billion years after the Big Bang. The gas is far hotter and more pressurised than current theories predicted for such a young system, forcing scientists to completely rethink how galaxy clusters evolved in the early universe. This discovery suggests that violent processes like supermassive black hole outbursts and intense starbursts heated these cluster atmospheres much earlier and more efficiently than anyone expected, fundamentally challenging our understanding of how the universes largest structures formed.