Shifting our clocks an hour naturally makes for a few groggy mornings, but some research suggests a far more dangerous impact to our bodies—an increased risk of heart attack. A 2012 study by University of Alabama at Birmingham's Martin Young found that the risk of heart attack surges by 10 percent on the Monday and Tuesday after moving the clocks ahead an hour each spring.
"Exactly why this happens is not known but there are several theories," Young said in a statement accompanying the study.
"Sleep deprivation, the body's circadian clock, and immune responses all can come into play when considering reasons that changing the time by an hour can be detrimental to someone's health."