Kids Should Only Be in the Snow For Short Periods, According to Doctors 22 Shares Kids love to play in the snow — building snow forts, having snowball fights, and even eating snow — but how long is it safe for little ones to be outside in extremely cold weather? With a large chunk of the US facing record lows, more and more parents are asking themselves this question. POPSUGAR talked to doctors to get an answer. How Long Can Kids Stay out in the Snow? Board-certified pediatrician Amna Husain, MD, told POPSUGAR that smaller bodies have a harder time with thermoregulation, or body temperature regulation. "The younger the child, the smaller the ratio of body mass to the body surface, meaning more heat can escape through his or her skin," Dr. Husain explained, noting that the length of time a child can safely spend outside in the snow depends on both the child's size and their ability to communicate how cold they feel.