Daylight saving time is a killer.
The annual ritual in which we trade an hour of morning light for evening brightness may seem like a harmless shift.
But each year, on the Monday after this springtime switch, hospitals report a 24% spike in heart attack visits around the country.
Just a coincidence? Probably not. Doctors see the opposite trend in the fall: on the Tuesday after we turn back the clocks, heart attack visits drop 21% as people get a little extra pillow time.
The reason that springing the clocks forward can kill us comes down to interrupted sleep schedules. This Sunday, instead of the clock turning from 1:59 to 2:00 a.m. as usual, it will jump an hour to 3:00 a.m.
Researchers estimate we’ll all deprive ourselves of an extra 40 minutes of sleep because of this.
“That’s how fragile and susceptible your body is to even just one hour of lost sleep,” sleep expert Matthew Walker, author of How We Sleep, previously told Business Insider.
Walker said this “global experiment” we perform twice a year is a sign of how sensitive our bodies are to the whims of changing schedules: in the fall, the shift is a blessing, and in the spring, it’s a fatal curse.
The tragic heart attack trend only lasts about a day, but our bodies may not fully recover from the springtime bump for weeks. We’re also prone to make more deadly mistakes on the roads. Researchers estimate that car crashes in the US caused by sleepy daylight-saving drivers likely cost 30 extra people their lives over the nine-year period from 2002-2011.
“The brain, by way of attention lapses and micro-sleeps, is just as sensitive as the heart to very small perturbations of sleep,” Walker explains in his book.
The problems don’t stop there. DST also causes more reports of injuries at work, more strokes, and may lead to a temporary bump in suicides at this time of year, too.