Christa Webster doesn't trust her hotel towels. And with good reason.

She lived in a hotel for a year-and-a-half, and still travels frequently. Webster says your hotel towel isn't clean just because it's folded on the rack. Once unfurled, she, like other hotel guests I've spoken with, has discovered a towel in various states of uncleanliness -- soiled, discolored or covered with hair.

"I inspect them carefully and then wet the ones I'm getting rid of to make sure they give me new ones," she says.

I recently investigated the hygiene of hotel sheets on this site, discovering that while most linens are changed between guests, some aren't. After the series, readers urged me to look at towels, too. They said towels could be a far bigger problem, since hotels often urge guests to recycle those items.

Here's what should happen: The standard operating procedure is for towels and sheets to be changed between every guest, according to Joe McInerney, president of the American Hotel & Lodging Association ( Towels are also swapped out every day at some, but not all properties.

"Some do, some don't," he says. "It's a management decision."

But what about the hotels with the little signs that encourage you to re-use your towels? McInerney says housekeepers generally err on the side of not recycling, because changing towels is something so ingrained in their training.

I wondered about one scenario in particular, which several readers had brought to my attention: What happens on the day of checkout, when your room is serviced in the morning and you leave a few hours later. Say you washed your hands and used the edge of one of the clean towels, without disturbing the folds. Will your hotel still change it?

"If they don't look like they have been disturbed, the towels are not changed out between guests," says Richard Adie, the general manager of The Statler Hotel at Cornell University. "It certainly depends on the judgment of the housekeeper."

So it's possible -- however remotely -- that you could end up with a towel another guest has used. But McInerney says it's unlikely. "Most guests aren't that tidy, and housekeepers can tell when a towel has been used," he says.

At some hotels, guests suspect housekeepers are rewarded for changing as few towels as possible. Mary Rhoades, who recently traveled to Houston for a Scrabble tournament, found her hotel only offered one set of towels. She was sharing the room with another attendee. Repeated requests for a new set were not answered. Finally, she swiped a new set from a housekeeping cart.

"After my roommate complained in person to the desk, we were given vouchers for a comped breakfast," she says.

Some travelers take extra precautions, just in case they check into a room with slightly-used towels. Jo Gilbert, a frequent traveler, says most of her towels have been clean. "In some cases, I'm better off with my quick-dry travel towel," she adds.

Christopher Elliott is the author of the upcoming book "Scammed: How to Save Your Money and Find Better Service in a World of Schemes, Swindles, and Shady Deals" (Wiley). He's also the ombudsman for National Geographic Traveler magazine and the co-founder of the Consumer Travel Alliance, a nonprofit organization that advocates for travelers. You can read more travel tips on his blog, E-mail him at