When these people get up for work, they keep going up.
Many an urban dweller has marvelled at window washers riding scaffolds that descend glass cliffs tens of stories tall. Or at high-steel construction crews walking the girders of skeletal buildings.
Then there are those who inspect the rivets on suspension bridges, roughnecks perched on towering off-shore oil rigs - even bungee-jumping instructors urging their wards to plunge off some precipice.
When the Monitor checked in with a handful of Americans who hold down dizzying gigs, the edge was taken off the perception that altitude translates to excessive on-the-job danger.
Chalk it up to intense training and extra precautions: Jobs like the ones we examined have some of the best safety records around.
Midway up the spire of the First Universalist Church, in Rockport, Mass., steeplejack Eric Morin balances precariously in a bosun's chair as he tosses a line around the steeple. From the street, Bion Pike tugs the heavier rope tied to the tail end of Mr. Morin's line to free it from a snag on the roof.
Mr. Pike points out that this is the most dangerous time in the job. Morin, working without a lifeline, is installing the cable from which all lines, including the lifelines to which the three-man crew will be attached as they restore the church steeple.
"This is just a job," says Pike. It's one they love doing, but none of them is in it for the excitement. "The 'adrenaline rush' has no place on a job like this," insists Pike. "The guys will tell you we aren't afraid of heights, we are respectful of heights."
Pike enjoys having a hand in maintaining a part of New England's history. Eric Morin, on the other hand, is a third-generation steeplejack and can't imagine doing anything else.
Dan Morin, uncle to Eric, keeps climbing steeples because it's different, he says, each time he goes up. One day he might be scraping and painting, another day he could be doing the delicate work of gold leafing. "I'm a jack of all trades," says Dan.
For a man who had never set foot on a sailboat, landing the job as a ship manager of an 1877 three-masted, iron-hulled sailing vessel was quite a career change.
Robert Wheeler was introduced to the "Elissa" 10 years ago when he signed on as one of the hundreds of volunteers who sail and maintain the tall ship.
The vessel - a restored ship with a history of transporting bananas to Galveston, Texas, and cotton to Europe - is anchored at the Texas Seaport Museum. Today, it is fully functional and carries guests of the museum, typically donors, around the Gulf of Mexico.
As ship manager, Wheeler ensures that the Elissa is in excellent sailing condition at all times. He is frequently aloft checking out the rigging. "The highest point on the Elissa," says Mr. Wheeler, "is the royal yardarm, at about 87 feet above the deck. And the deck is about 14 feet above sea level."
He trains volunteers in every aspect of the ship's workings. Not such an easy task when no cranes or motors are used to maintain the ship. In its time, Elissa was the top-of-the-line sailing vessel.
The volunteers must be able to demonstrate that they have the upper-body strength required to work aloft. The volunteers sand and varnish the yardarms and masts, they haul the sails into the rigging in preparation for the sailing season, and they maintain and repair the rigging and sails throughout the year.
Wheeler laughed at an observation made by one of his instructors: "New volunteers hang on so tightly you couldn't get them off with a hammer."
Being part of something bigger than himself is very satisfying, says Wheeler. But more than anything, "I love to be climbing around in the ship's rigging. It's like a great big jungle gym."
Rick Watson's passion for wildlife conservation has taken him to the Madagascar rain forest. A biologist with the Peregrine Fund in Boise, Idaho, Mr. Watson spent seven years during the '90s observing three bird species about 120 feet up in the forest canopy.
His initial climb required the use of a crossbow to send up a fishing line. That line helped haul up a climbing rope.
After climbing up the rope, he and his colleagues constructed a a blind and established a rope system that acted as a safety net when they traversed the canopy.
Watson doesn't like heights, but he'll climb to the canopy at dawn and down again at dusk if it means he can collect data that will help him understand why a bird is so rare. "I just don't look down." The height wasn't the worst part, he says. It was always being wet and hot.
Watson, who today manages the Peregrine Fund's programs around the world, described a recent rescue. The goal: to save a bearded vulture nestling in Ethiopia from siblicide - a phenomenon among large raptors - and release it, as a fledgling, in Kenya, where the species is almost extinct. The nest was midway down a thickly forested 1,000-foot cliff in Ethiopia. So as the nestling's liberator was lowered by rope, he had to carefully slash through dense growth without hacking up his rope - while avoiding possible attack from the adult raptors.
Watson was content to be the administrator on that job.