Daylight saving time changes what "time" the sun rises and sets, affecting daily light exposure. This is known as a circadian rhythm — our predictable, 24-hour cycle of physical, mental and behavioral changes regulated by daylight. Sleep is a key component of the circadian rhythm and is often influenced by environmental factors such as light. Researchers say throwing that biological clock out of sync has adverse health effects, including increased risk of heart attack and ischemic stroke, according to a 2019 study from Vanderbilt University Medical Center. Dr. Lisa Barber, a pediatric pulmonologist at Dell Children's in Austin joins In Focus Texas to talk about how ‘springing forward’ affects health and well-being.