Perhaps the woman should have known better, but she had traveled to great heights before--in Colorado and the Sierras, in Peru and Nepal.
She wanted to see the star-gazing gear on the summit of Mauna Kea, the bold volcanic mountain that rises 13,796 feet above the sea on the Big Island of Hawaii.
Perhaps the woman should have stayed at the 9,200-foot level, in the Visitors Center named for astronaut Ellison S. Onizuka, who was born on the Big Island and died in the 1986 Challenger disaster.
That is the elevation at which astronomers acclimatize when coming from sea level to work on the summit. That is the point where the asphalt ends and four-wheel-drive vehicles become mandatory.
As the steep road turned to rubble and her fingertips turned to blue, she said to the driver: "Maybe I should get out and wait for you by the side of the road."
"Maybe you should try oxygen," he replied firmly, handing her a small tank and nose piece and adjusting the valve. "You'll feel a hundred times better in a few minutes."
She looked out at the raw red land that fell away on all sides, at the sheer lava-and-cinder bowls where moon-landing craft had been tested. She paced her breathing. She told herself not to panic.
The van ground into its lowest gear and slowed to five m.p.h. The cheery young driver talked on.
"My dad was a stunt man in Hollywood for 15 years before he started these mountain tours out of Kamuela," he said. "He broke his back and knees and ankles. The man is walking Teflon. I did some film stunts as a kid myself."
But now he was playing it straight. He kept his eyes on the road; the woman kept her eyes on his neck. The van lurched around a final turn and emerged on top of the world.
All was silent and blazed with sun. Stark white observatories stood like chess pieces against a deep blue sky; patches of snow lay snagged on barren, black ridges.
There were no clouds above, where the telescopes would scan the heavens that night. But down the slopes, like a fluffy collar, a cumulous ring cut the summit off from the coastal plain, creating an island above an island.
Others piled out of the van to survey the clean, bright world and take photographs of the high-profile crater Haleakala that loomed to the north on Maui. They laughed and buttoned their jackets against the brisk winds of summer.
But the woman stayed inside with her oxygen tank and stared at the eerie scene through wide windows.
"Good move," the driver said. "A little exertion goes a long way up here. The air contains 38% less oxygen than at sea level. Thin, dry air.
"It's perfect working conditions for astronomers, but it can be hard on visitors because the change in altitude is so sudden. We came up 5,000 feet in the last eight miles. Don't ever drink a beer up here; you'll really feel it. Want some water?"
'Started to Sleet'
Observatory tours had been scrubbed because of a power outage, the driver learned from a technician. "This mountain is fluky," he said. "Last week when we were in looking at a telescope, it started to sleet. When we came out, the doors of the van were frozen shut. I had to use a knife to chip my way in."
The driver pointed out the 88-inch telescope that the University of Hawaii shares with NASA. He identified observatories operated by Canada, France, the United Kingdom, the Netherlands and Japan.
In 1991, he said, the world's largest optical and infrared telescope is scheduled for completion atop Mauna Kea: the University of California and Caltech's W. M. Keck Observatory, with four times the light-gathering power of the 200-inch telescope at the Palomar Observatory.
The timing, they hope, will be perfect. That is the year of a solar eclipse and Hawaii, just 20 degrees north of the Equator, is set for a stunning view. Blocks of resort rooms on the Big Island have been reserved already. A few travelers will get to see the phenomenon from Mauna Kea State Park halfway down the slope, where cabins--with kitchen and fireplace--are for rent at about $14 a night double.
The state park is below the Visitors Center down by the Saddle Road, where eucalyptus trees grow and there are sightings of quail and nene, the endangered Hawaiian goose that is making a comeback.
It was near this park that the woman's fingers turned rosy pink again and she returned the oxygen tank to the driver.
It was here that she ate her sandwich and taro chips and began once again to take notes.
It was here that she learned that Mauna Kea is more than the largest island mountain in the world. If measured from the ocean floor, it is taller even than Everest.
And she learned that children under 16 are not allowed on summit tours because of possible health hazards. And that scuba divers must wait at least 24 hours after diving before traveling to the summit to avoid the danger of the bends.
And that if you have a chest cold--which she did--you should think twice about making the ascent.
Perhaps the woman should have known better. But, thanks to a sensitive driver and a boost of oxygen, what she didn't know didn't hurt her.