"Know one lost sleep hour raises heart risk Walker points to a natural experiment run on 1.6 billion people twice a year — daylight saving time — as stark proof of sleep's cardiovascular impact. In spring, when one hour of sleep is lost, there is "a subsequent 24 percent increase in heart attacks that following day," while in autumn, when one hour is gained, heart attacks drop by 21 percent. The same pattern holds for road traffic accidents and suicide rates. This data makes clear that even a single hour of sleep loss is not a trivial inconvenience but a measurable physiological stressor with life-or-death consequences. Source: Matt Walker, TED, Sleep is your superpower"