Stray bullets and wayward arrows pose the most well-known dangers to hunters, but with deer season upon us, doctors warn of a more perilous threat: buck fever. That's the phenomenon that each season causes scores of heart attacks in hunters overexcited by the sighting or shooting of a deer, or overcome by the exertion of dragging their kill out of the woods.

"Hunting is much more strenuous than we imagined," says Susan Haapaniemi, an exercise physiologist at William Beaumont Hospital in Royal Oak, Mich. Over the last few years Haapaniemi and her colleagues have strapped monitors on 25 middle-aged male hunters who had at least one complicating health condition (high cholesterol, high blood pressure, diabetes, a smoking habit, a sedentary lifestyle or a family history of heart disease) and discovered that when a deer came into view the men's heart rates jumped to as much as twice their normal rates.
—Kostya Kennedy, "Bambi's Revenge," Sports Illustrated, November 24, 1997

In a two-year study, researchers at William Beaumont Hospital in Royal Oak found hunting's effects on the heart can exceed those of stress testing in a cardiac laboratory.

"Our whole point is to show that deer hunting is very strenuous and that hunters are a very high-risk population," explains Sue Haapaniemi, a William Beaumont exercise physiologist who spearheaded the research. "So if you've got a high-risk person doing an activity that has moments of sudden exercise, those people, very much, are heart attack risks." In other words, being in poor physical condition can result in a hunter — rather than a trophy buck — being dragged out of the forest.

They call it "buck fever."
—Mark Emmons, "The beast that stalks the hunter," Detroit Free Press, October 1, 1996