Getting adequate rest helps your immune system perform at its best. Aim to get 7-9 hours of sleep every night. Try techniques to improve your sleep habits:  Set a regular bedtime and wake up time. Exercise regularly (but not within 3 hours of bedtime so it doesn’t keep you up). Avoid caffeine after 4pm. Avoid napping during the day. Relax before bed with a warm bath or reading. Save your bedroom for sleeping – don’t watch TV in bed. Sleep in a cool, dark room. Eating a nutritious and varied diet helps your immune system work. Think about eating a “colorful” diet – one high in fresh fruits and vegetables of many different colors. This can help you get lots of vitamins and nutrients to keep your body healthy. Stay hydrated to maintain your overall health and  avoid getting sick. In general, men should drink around 13 cups of water and other fluids daily (about 3 liters), and women should aim for 9 cups (2.2 liters). Drink more if you sweat a lot. Water, juice, and tea count towards your fluids. Aerobic workouts are those that increase your heart rate and breathing rate. Walking, slow jogging, biking, and swimming are good options. Aim to get at least 30 minutes of aerobic activity at least 5 days per week for optimal health. This won't stop the flu, but it can keep you healthy and make recovery easier. You may have to get creative to exercise during the winter. Get a gym membership, go dancing, use workout videos at home, find an indoor pool – do what you can to stay active in the winter. . The stress hormone cortisol negatively affects numerous body systems – including your immune system. Try yoga, meditation, deep breathing, taking a walk – anything that helps you relax. If you have a stressful lifestyle due to work or family, practice mindfulness meditation or learn stress management skills. While it won't stop

Summary:
Sleep 7-9 hours a night. Eat a nutritious diet. Drink enough water. Stay active. Decrease your stress level