Flying is like giving blood. Not just because for both things a person has to put her head where a multitude of others have put theirs.

Flying is like giving blood. Not just because for both things a person has to put her head where a multitude of others have put theirs.

It's like giving blood because the run-up to both activities is far more complicated and time-consuming than the activities themselves, and also because the run-up is always changing, never the same rules twice, which keeps people off balance and on the defensive. I wouldn't accuse the Red Cross of liking it that way, but I do have an eentsy-beentsy suspicion that airline security personnel love making passengers feel dumb and clumsy.

This suspicion got a dose of Miracle-Gro during a recent trip to and from Maine, via New York and Philadelphia. Having learned last year during trips both east and west what's expected at airport security checkpoints I learned by doing everything wrong I thought I'd breeze through the procedure this time. I heaved my suitcase directly onto the belt instead of trying to squeeze it into a plastic tub; I remembered to put my plastic bag with its miniature shampoo and conditioner containers into the tub along with my shoes; I remembered to take off my jacket, because nobody at airport security cares that it's part of my ensemble.

But when I prepared to walk through the metal detector, it wasn't there. Or rather, the simple arch had morphed into another detecting device, one that looked like a cross between a refrigerator and a tall, narrow movie screen. One of my travel companions was even now standing under the arch of the new device, facing the screen and holding her hands on her head.

I observed this new rite of passage with trepidation. I'd read stories about the whole-body scanner how it performs a "virtual strip search" and produces pictures of passengers that would make their own doctors blush.

"Whole-body imaging technologies can see through clothing to reveal metallic and non-metallic objects They also reveal a person's silhouette and the outlines of underwear," according to the website LiveScience.

The mention of underwear was both reassuring at least it was still there and alarming (in my world, anything that goes under might be in less than great condition).

These were disturbing thoughts to have moments before I was beckoned into the device myself. The beckoner was a burly guy in an airport security uniform.

"He's just like a doctor," I told myself, though nobody less like a doctor had ever told me to stand facing a screen.

"Put your thumbs on your head," the burly guy said.

I'm nothing if not obedient, especially when receiving orders from unsmiling uniformed guard-types, and I immediately put my hands on my head.

Then I underwent a terrible moment of indecision. Thumbs on head, thumbs on head. Did he mean "thumbs on head with other fingers wrapped protectively around them"? Or did he mean "thumbs on head where I can see them," the way sheriff's deputies in movies are always saying "Hands up where I can see them"?

Before he could jerk me off the flight for failure to obey commands, I planted both my thumbs on the top of my head and opened my hands wide, as if to say "See, nothing to hide here!"

Too late, I realized the image he was seeing from his end was not that of a confident, experienced traveler, cool with all technology and possessing enough poise to override any underwear condition issues. The image he was seeing was nothing so much as Mickey Mouse. No, Minnie. To be precise.

"Okay," he said without expression. I stepped out of the metal arch with what I hoped was dignity, claimed my things as they emerged from the scanner and paused at a bench to put on my shoes.

"Don't worry," said the friend who had preceded me into the arch. "He sees this stuff all the time; he's just like a doctor."

What the heck. I decided to believe her.

Margo Bartlett is a ThisWeek staff writer. Email mbartlett@ thisweeknews.com.