Deep in Chile’s Atacama Desert, scientists studied a green crystal called atacamite—and discovered it can cool itself dramatically when placed in a magnetic field. Unlike a regular fridge, this effect doesn’t rely on gases or compressors. Instead, it’s tied to the crystal’s unusual inner structure, where tiny magnetic forces get tangled in a kind of “frustration.” When those tangled forces are disrupted by magnetism, the crystal suddenly drops in temperature. It’s a strange, natural trick that could someday help us build greener, more efficient ways to cool things.