The benefits of outdoor activity are twofold. First, kids and adults who get daily exercise suffer significantly fewer colds and respiratory illnesses than those who don’t, according to a 2011 study by the University of Wisconsin Department of Family Medicine. Second, individuals with low levels of vitamin D were much more likely to get sick than those who took a vitamin D supplement and got regular exposure to sunshine. So, bundle up and get outside! Go for a walk, play in the snow or build a snowman. Older kids can even help shovel the driveway.