Get ready to ensure and protect your holiday fun by saving space in your suitcase or carry-on for smart tools that let you stay ahead of seasonal-travel health hazards. They’ll help you fight off colds and flu viruses, digestive-system discomforts, sleep problems and extra stress. That way, you’ll stay healthy on car trips and airline flights, during hotel stays and whenever you’re away from home.

Æ Take an empty plastic travel mug or water bottle, and a bag or two of healthy snacks. Tote a container for water: You can fill it up at a water fountain or bathroom tap after you’ve passed through airport security. Use it for water (or coffee or tea refills) on the plane, and again at your destination to stay hydrated while you're exercising. And for snacking, pack nuts, sliced red pepper, baby carrots and a piece of fruit in zipper-lock bags. Water and fiber-rich snacks keep your digestive system working right.

Æ Pack alcohol-based sanitizing wipes. We don't think hotel germs pose a huge risk to your health, but a recent report raised alarms about bacteria levels in even the fanciest hotels. Give light switches, sink faucets and the TV remote a quick rub-down with a sanitizing wipe. (Don't use anything that's labeled “antibacterial” -- those products contribute to antibiotic resistance, and alcohol does the job without causing problems.) Same goes for the table, if you plan to eat there. Bonus: Pull the top sheet, which is always freshly laundered, up over the edge of the bed covering or comforter (which usually is not washed between hotel guests), before you go to bed. The comforter was one of the germiest objects, next to light switches and TV remotes (you can always put those in a baggie and use them through the plastic).

Æ The holiday season is also the height of cold and flu season. Use hand sanitizer frequently as it's your first line of defense. And get your flu shot. Bonus: Popping 1,000 IU of vitamin D-3 daily can slash flu risk by half.

Æ Heading to a colder climate? Make room in your suitcase for a coat, sweater, hat, scarf, gloves and boots, even if you're not sure you'll need them. A dip in temperature from what you're used to increases your risk for stroke (7 percent) and heart attack (12 percent). Bonus: You'll be ready to de-stress by tossing snowballs or walking in a winter wonderland.

Æ Pack walking shoes and a heart-rate monitor. Short days, long nights and the year's lowest levels of natural light can conspire with travel strains and family dramas to deflate your mood. Comfortable, supportive walking shoes will help you take regular mood-boosting exercise breaks. Dr. Mike insists on an hour for exercise every day he's on the road. (That helps keep his RealAge younger.) Try walking breaks during long drives — a stay-sharp move that can help you remain alert in traffic. Also, stroll the aisle every hour on the plane, as Dr. Mike does. And use walking shoes and a heart-rate monitor to help you escape — er, exercise — outdoors when the holiday house gets too crowded.

Æ Take an alarm clock. Love staying up late to catch up with friends and family? Do your best to get up at your usual time. You'll slash your risk for post-holiday “social jet lag,” those groggy, early January days when your body clock tries to readjust to your regular schedule. Maintaining a consistent morning wake-up time, and getting morning exposure to sunlight, keeps your sleep-wake cycle set to “normal.” Grab an early-afternoon nap if you're tired; 26 minutes is ideal.

The You Docs — Mehmet Oz, host of “The Dr. Oz Show” and Mike Roizen of Cleveland Clinic — are authors of “YOU: Losing Weight.”