Fresh air and exercise are important for people of all ages, including babies. However, according to the American Academy of Pediatrics it is important to remember that young babies and toddlers lose heat more quickly than adults due to their small size. You should avoid taking a baby out in temps below -15 Fahrenheit (this includes taking wind chill into account), and keep time outside limited to 15 minute increments in very cold weather. You can watch for signs of frostbite or hypothermia, such as skin pallor or redness, shivering and shaking, crying, or sluggishness.