|NATIONAL PARKS QUICKLINKS|
Backpacker Magazine – December 2007
There's a backcountry killer on the loose, and it's not hypothermia, grizzly bears, or rockfall. The thing mostly likely to maim you on your next hiking trip is living inside your head.
Panic is the body's built-in alarm system to the threat of danger. In 1915, American physiologist Walter Cannon coined the phrase "fight-or-flight" to describe a series of bodily changes that occur in response to a real or perceived threat. First, signaled by the brain, the adrenal glands attached to your kidneys release a jolt of adrenaline, essentially shocking your system. Your heart begins to race, respiration becomes quick and shallow, hands and feet go cold. Pupils dilate, muscles become primed for action. The stomach shuts down digestion, and the liver releases a shot of stored-up sugar. All of this is evolutionarily designed to kick your body into lifesaving mode when you find yourself face-to-face with, say, a saber-toothed tiger. It's only in the last 20,000 years, the snap of a finger in evolutionary time, that humans have been the dominant predator on the planet. For the first 2 million years of our ever-morphing existence, our ancestors were often prey. And panic was a sensible survival mechanism.
Panic still serves a purpose in modern society—it fuels the woman who single-handedly fights off a rapist, the teenager who lifts the car off a sibling, the man who leaps into action to save schoolchildren on a collapsing bridge. But in the wilderness of today, with so few predators left, the fight-or-flight response is usually counterproductive. In most backcountry incidents, whether you're lost or injured, hungry or thirsty, two of the worst things you can do are fight or run. When you're lost, for instance, fighting manifests itself as an unwillingness to accept any physical or geographical cues that contradict your (unknowingly confused) internal sense of direction. The panicked mind reasons that the compass must be broken, the map must be old, the trail's going the wrong way. A panicking mind misreads reality.
"This is because the brain is being flooded with noradrenalin, or norepinephrine," says Dr. Kenneth Heilman, distinguished professor of neurology at the University of Florida in Gainesville. Norepinephrine is the brain's hormonal counterpart to the body's adrenaline. "Panic, what we could call excessive or extreme anxiety, has two components," Heilman explains, "physical and mental. What happens to the body is often readily recognizable, but what happens in the brain, precisely because it is in the brain, is almost invisible."