And next here tonight, some real answers about how to be with people and avoid all those colds this season and the flu. And tonight, the flu outbreak is still in 20 states. So, our question, how do... See More
And next here tonight, some real answers about how to be with people and avoid all those colds this season and the flu. And tonight, the flu outbreak is still in 20 states. So, our question, how do you get the least exposure? A hug? A handshake? A high-five? Abc's chief medical editor, dr. Besser, steps into the lab to tell us. Reporter: Here's the challenge. Can we answer the question, in a season of cold and flu, what's the best way to greet each other to protect ourselves? A handshake? A fist-bump? Or a high-five? For our experiment, I'm patient zero. My hands covered with bacteria, that will transfer like the dangerous germs that get you sick. These e. Coli aren't harmful. I shook hands with all of the volunteers in group one. Then, they pressed their hands into special plates that were ink b incubated overnight. And here's how I passed on to the first volunteer in line. She has almost as many as me. Let's watch what happens as she shakes hands with the next volunteer and so on and so forth. It takes four handshakes for the bacteria transfer to decrease. Even the last person in line got enough bacteria from my hands to get sick. Let's compare that to a fist-pump. I'm on the left. The plate on the right, the first fist-bump. Fist-bumps minimizes the surface area. And protects the fingers and palms from germs. And time also matters. Fist-bumps reduce the time your hands are in contact. What about a high-five. Here, the hands are touching. But the contact time is very short. Mine is on the left. The first high-five, on the right. The results, just about the same as the fist-bump. Both are much better than handshakes. During flu season, think of mixing up the way you say hello. So many of us seem to have gotten that message. Rich is here now. What about hugging? Hugging is good if you do it like these women. Looking over the shoulder, not going -to-face. If you're doing that, you're not going to be sharing a lot of germs. Pass the cheek and over the shoulder. You were telling me, the hand is so intense because you touch your eyes and your nose, if you rub your note as all. Your eyes and your nose is a window. It's an entry point into your body. A common way to get sick. To review your results. The worst things is handshakes. That's not good. Next is hugs because you may get a kiss thrown in. The best thing you can do, high-fives or my favorite, the fist-bump. If you're afraid of germs, an elbow never hurts. See you tomorrow.
This transcript has been automatically generated and may not be 100% accurate.