Rising temperatures linked to human-induced climate change are contributing to a growing global sleep deficit, with Japan currently experiencing particularly hot and sleepless nights as summer arrives. The phenomenon isn’t limited to Japan, however, and indicates a broader international trend. Scientists attribute the increasing nighttime temperatures to the effects of global warming, disrupting natural sleep patterns. Insufficient sleep has widespread consequences for both individual health and societal productivity. This issue adds another layer to the already significant impacts of climate change, impacting well-being worldwide. Addressing climate change is therefore increasingly vital not only for environmental reasons, but also for public health.