A friend once told Andy Powell that "Stupid should hurt."

But read any product warning label and you'll realize that stupid has hurt - someone, somewhere.

Consider, for instance, the now-common advice printed on windshield shades: "Remove shade before operating vehicle."

"I've been guilty of driving in the winter with a bit of frost on my windshield," writes Powell, "but someone must have decided to drive with the sunshade up, right?"

Powell is clearly smarter than that someone. With pal Jeff Koon, he's written a book to capitalize on such half-wits. Their Wearing of This Garment Does Not Enable You To Fly: 101 Real Dumb Warning Labels (Free Press, $12.95) offers a selection of product warnings so ludicrous that all you need is a drum roll to turn them into punchlines.

A fireworks package warns: "Caution flammable. Do not put in mouth." (Talk about your powerful breath fresheners.)

A microwave maker, obviously aware of some seriously twisted activity with its product, admonishes: "At no time should anyone be allowed to lean or swing on the oven door. The oven is for food preparation only. It should not be used to dry clothes or newspapers." (And to think we've been sticking to your basic frozen dinners . . .)

And as for the poor souls in need of Boudreaux's Butt Paste, we can only say that we wholeheartedly endorse this warning: "Avoid contact with eyes."

It all goes to show that just when you think the masses have sunk to an all-time low, someone out there finds the next level.

As writer Elbert Hubbard once said: "Genius may have its limitations, but stupidity is not thus handicapped."

Patti Thorn, books editor