'Tis the season for getting fat. While the holidays are one of the most exciting times of the year, they can also be the most stressful as people worry about their waist lines. Popular Science's Rachel Feltman joins us with tips on how to fend off the "frozen fifteen." She says it can take people up to six months to lose the weight they gain over the holidays. Follow her tips so you can stay at your pre-Thanksgiving weight. Then, Feltman tells us about a new lawsuit against Sephora. A woman claims she contracted herpes from trying a lipstick sample. Feltman says this is a myth, and it's incredibly rare to get the virus from makeup. It's much more likely you'd get it from skin-to-skin contact, or through saliva, so no need to wear a hazmat suit the next time you try on a new shade. Finally, we tackle the age-old question of what exactly is happening when you get a "stitch" in your side while exercising. While it happens to everyone, stitches are actually not widely researched by scientists. Feltman tells us what's going on underneath the skin and how you can avoid getting one the next time you work out.