You have probably been told to bundle up in cold weather so that you don’t become sick. The truth is, cold weather or not, it takes exposure to a virus or bacteria to cause an infection. In fact, going outside and getting more physical activity can prevent sickness. One reason why infections may become more prevalent during cold, wet weather is that more people spend time indoors, clustering together and increasing the likelihood of transmission from one person to another. Getting more rest is a good thing to help a weakened immune system. Your local healthfood/supplement store can also advise you on how to keep your immune system healthy.