He said the hair dryer was one thing that surprised him.
"There must be some things you can do with a hair dryer that I am not aware of because some of them were pretty germy," Gerba said.
Not only are you touching the hairdryer which is potentially laden with germs, you are blowing them through your hair, on your face and on your head.
Another thing Gerba identified as particularly germy was the hotel menu.
"They [hotel guests] flip through the pages,” he said. “They put their fingers here. So, you are more likely to find something here."
If you are concerned about germs in your hotel, bring some antibacterial wipes with you and remember – even if it looks clean, it doesn’t mean it is.